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    1 
    2 		    GNU GENERAL PUBLIC LICENSE
    3 		       Version 2, June 1991
    4 
    5  Copyright (C) 1989, 1991 Free Software Foundation, Inc.
    6  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
    7  Everyone is permitted to copy and distribute verbatim copies
    8  of this license document, but changing it is not allowed.
    9 
   10 			    Preamble
   11 
   12   The licenses for most software are designed to take away your
   13 freedom to share and change it.  By contrast, the GNU General Public
   14 License is intended to guarantee your freedom to share and change free
   15 software--to make sure the software is free for all its users.  This
   16 General Public License applies to most of the Free Software
   17 Foundation's software and to any other program whose authors commit to
   18 using it.  (Some other Free Software Foundation software is covered by
   19 the GNU Library General Public License instead.)  You can apply it to
   20 your programs, too.
   21 
   22   When we speak of free software, we are referring to freedom, not
   23 price.  Our General Public Licenses are designed to make sure that you
   24 have the freedom to distribute copies of free software (and charge for
   25 this service if you wish), that you receive source code or can get it
   26 if you want it, that you can change the software or use pieces of it
   27 in new free programs; and that you know you can do these things.
   28 
   29   To protect your rights, we need to make restrictions that forbid
   30 anyone to deny you these rights or to ask you to surrender the rights.
   31 These restrictions translate to certain responsibilities for you if you
   32 distribute copies of the software, or if you modify it.
   33 
   34   For example, if you distribute copies of such a program, whether
   35 gratis or for a fee, you must give the recipients all the rights that
   36 you have.  You must make sure that they, too, receive or can get the
   37 source code.  And you must show them these terms so they know their
   38 rights.
   39 
   40   We protect your rights with two steps: (1) copyright the software, and
   41 (2) offer you this license which gives you legal permission to copy,
   42 distribute and/or modify the software.
   43 
   44   Also, for each author's protection and ours, we want to make certain
   45 that everyone understands that there is no warranty for this free
   46 software.  If the software is modified by someone else and passed on, we
   47 want its recipients to know that what they have is not the original, so
   48 that any problems introduced by others will not reflect on the original
   49 authors' reputations.
   50 
   51   Finally, any free program is threatened constantly by software
   52 patents.  We wish to avoid the danger that redistributors of a free
   53 program will individually obtain patent licenses, in effect making the
   54 program proprietary.  To prevent this, we have made it clear that any
   55 patent must be licensed for everyone's free use or not licensed at all.
   56 
   57   The precise terms and conditions for copying, distribution and
   58 modification follow.
   59 
   60 		    GNU GENERAL PUBLIC LICENSE
   61    TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
   62 
   63   0. This License applies to any program or other work which contains
   64 a notice placed by the copyright holder saying it may be distributed
   65 under the terms of this General Public License.  The "Program", below,
   66 refers to any such program or work, and a "work based on the Program"
   67 means either the Program or any derivative work under copyright law:
   68 that is to say, a work containing the Program or a portion of it,
   69 either verbatim or with modifications and/or translated into another
   70 language.  (Hereinafter, translation is included without limitation in
   71 the term "modification".)  Each licensee is addressed as "you".
   72 
   73 Activities other than copying, distribution and modification are not
   74 covered by this License; they are outside its scope.  The act of
   75 running the Program is not restricted, and the output from the Program
   76 is covered only if its contents constitute a work based on the
   77 Program (independent of having been made by running the Program).
   78 Whether that is true depends on what the Program does.
   79 
   80   1. You may copy and distribute verbatim copies of the Program's
   81 source code as you receive it, in any medium, provided that you
   82 conspicuously and appropriately publish on each copy an appropriate
   83 copyright notice and disclaimer of warranty; keep intact all the
   84 notices that refer to this License and to the absence of any warranty;
   85 and give any other recipients of the Program a copy of this License
   86 along with the Program.
   87 
   88 You may charge a fee for the physical act of transferring a copy, and
   89 you may at your option offer warranty protection in exchange for a fee.
   90 
   91   2. You may modify your copy or copies of the Program or any portion
   92 of it, thus forming a work based on the Program, and copy and
   93 distribute such modifications or work under the terms of Section 1
   94 above, provided that you also meet all of these conditions:
   95 
   96     a) You must cause the modified files to carry prominent notices
   97     stating that you changed the files and the date of any change.
   98 
   99     b) You must cause any work that you distribute or publish, that in
  100     whole or in part contains or is derived from the Program or any
  101     part thereof, to be licensed as a whole at no charge to all third
  102     parties under the terms of this License.
  103 
  104     c) If the modified program normally reads commands interactively
  105     when run, you must cause it, when started running for such
  106     interactive use in the most ordinary way, to print or display an
  107     announcement including an appropriate copyright notice and a
  108     notice that there is no warranty (or else, saying that you provide
  109     a warranty) and that users may redistribute the program under
  110     these conditions, and telling the user how to view a copy of this
  111     License.  (Exception: if the Program itself is interactive but
  112     does not normally print such an announcement, your work based on
  113     the Program is not required to print an announcement.)
  114 
  115 These requirements apply to the modified work as a whole.  If
  116 identifiable sections of that work are not derived from the Program,
  117 and can be reasonably considered independent and separate works in
  118 themselves, then this License, and its terms, do not apply to those
  119 sections when you distribute them as separate works.  But when you
  120 distribute the same sections as part of a whole which is a work based
  121 on the Program, the distribution of the whole must be on the terms of
  122 this License, whose permissions for other licensees extend to the
  123 entire whole, and thus to each and every part regardless of who wrote it.
  124 
  125 Thus, it is not the intent of this section to claim rights or contest
  126 your rights to work written entirely by you; rather, the intent is to
  127 exercise the right to control the distribution of derivative or
  128 collective works based on the Program.
  129 
  130 In addition, mere aggregation of another work not based on the Program
  131 with the Program (or with a work based on the Program) on a volume of
  132 a storage or distribution medium does not bring the other work under
  133 the scope of this License.
  134 
  135   3. You may copy and distribute the Program (or a work based on it,
  136 under Section 2) in object code or executable form under the terms of
  137 Sections 1 and 2 above provided that you also do one of the following:
  138 
  139     a) Accompany it with the complete corresponding machine-readable
  140     source code, which must be distributed under the terms of Sections
  141     1 and 2 above on a medium customarily used for software
  142     interchange; or,
  143 
  144     b) Accompany it with a written offer, valid for at least three
  145     years, to give any third party, for a charge no more than your
  146     cost of physically performing source distribution, a complete
  147     machine-readable copy of the corresponding source code, to be
  148     distributed under the terms of Sections 1 and 2 above on a medium
  149     customarily used for software interchange; or,
  150 
  151     c) Accompany it with the information you received as to the offer
  152     to distribute corresponding source code.  (This alternative is
  153     allowed only for noncommercial distribution and only if you
  154     received the program in object code or executable form with such
  155     an offer, in accord with Subsection b above.)
  156 
  157 The source code for a work means the preferred form of the work for
  158 making modifications to it.  For an executable work, complete source
  159 code means all the source code for all modules it contains, plus any
  160 associated interface definition files, plus the scripts used to
  161 control compilation and installation of the executable.  However, as a
  162 special exception, the source code distributed need not include
  163 anything that is normally distributed (in either source or binary
  164 form) with the major components (compiler, kernel, and so on) of the
  165 operating system on which the executable runs, unless that component
  166 itself accompanies the executable.
  167 
  168 If distribution of executable or object code is made by offering
  169 access to copy from a designated place, then offering equivalent
  170 access to copy the source code from the same place counts as
  171 distribution of the source code, even though third parties are not
  172 compelled to copy the source along with the object code.
  173 
  174   4. You may not copy, modify, sublicense, or distribute the Program
  175 except as expressly provided under this License.  Any attempt
  176 otherwise to copy, modify, sublicense or distribute the Program is
  177 void, and will automatically terminate your rights under this License.
  178 However, parties who have received copies, or rights, from you under
  179 this License will not have their licenses terminated so long as such
  180 parties remain in full compliance.
  181 
  182   5. You are not required to accept this License, since you have not
  183 signed it.  However, nothing else grants you permission to modify or
  184 distribute the Program or its derivative works.  These actions are
  185 prohibited by law if you do not accept this License.  Therefore, by
  186 modifying or distributing the Program (or any work based on the
  187 Program), you indicate your acceptance of this License to do so, and
  188 all its terms and conditions for copying, distributing or modifying
  189 the Program or works based on it.
  190 
  191   6. Each time you redistribute the Program (or any work based on the
  192 Program), the recipient automatically receives a license from the
  193 original licensor to copy, distribute or modify the Program subject to
  194 these terms and conditions.  You may not impose any further
  195 restrictions on the recipients' exercise of the rights granted herein.
  196 You are not responsible for enforcing compliance by third parties to
  197 this License.
  198 
  199   7. If, as a consequence of a court judgment or allegation of patent
  200 infringement or for any other reason (not limited to patent issues),
  201 conditions are imposed on you (whether by court order, agreement or
  202 otherwise) that contradict the conditions of this License, they do not
  203 excuse you from the conditions of this License.  If you cannot
  204 distribute so as to satisfy simultaneously your obligations under this
  205 License and any other pertinent obligations, then as a consequence you
  206 may not distribute the Program at all.  For example, if a patent
  207 license would not permit royalty-free redistribution of the Program by
  208 all those who receive copies directly or indirectly through you, then
  209 the only way you could satisfy both it and this License would be to
  210 refrain entirely from distribution of the Program.
  211 
  212 If any portion of this section is held invalid or unenforceable under
  213 any particular circumstance, the balance of the section is intended to
  214 apply and the section as a whole is intended to apply in other
  215 circumstances.
  216 
  217 It is not the purpose of this section to induce you to infringe any
  218 patents or other property right claims or to contest validity of any
  219 such claims; this section has the sole purpose of protecting the
  220 integrity of the free software distribution system, which is
  221 implemented by public license practices.  Many people have made
  222 generous contributions to the wide range of software distributed
  223 through that system in reliance on consistent application of that
  224 system; it is up to the author/donor to decide if he or she is willing
  225 to distribute software through any other system and a licensee cannot
  226 impose that choice.
  227 
  228 This section is intended to make thoroughly clear what is believed to
  229 be a consequence of the rest of this License.
  230 
  231   8. If the distribution and/or use of the Program is restricted in
  232 certain countries either by patents or by copyrighted interfaces, the
  233 original copyright holder who places the Program under this License
  234 may add an explicit geographical distribution limitation excluding
  235 those countries, so that distribution is permitted only in or among
  236 countries not thus excluded.  In such case, this License incorporates
  237 the limitation as if written in the body of this License.
  238 
  239   9. The Free Software Foundation may publish revised and/or new versions
  240 of the General Public License from time to time.  Such new versions will
  241 be similar in spirit to the present version, but may differ in detail to
  242 address new problems or concerns.
  243 
  244 Each version is given a distinguishing version number.  If the Program
  245 specifies a version number of this License which applies to it and
  246 "any later version", you have the option of following the terms and
  247 conditions either of that version or of any later version published by
  248 the Free Software Foundation.  If the Program does not specify a
  249 version number of this License, you may choose any version ever
  250 published by the Free Software Foundation.
  251 
  252   10. If you wish to incorporate parts of the Program into other free
  253 programs whose distribution conditions are different, write to the author
  254 to ask for permission.  For software which is copyrighted by the Free
  255 Software Foundation, write to the Free Software Foundation; we sometimes
  256 make exceptions for this.  Our decision will be guided by the two goals
  257 of preserving the free status of all derivatives of our free software and
  258 of promoting the sharing and reuse of software generally.
  259 
  260 			    NO WARRANTY
  261 
  262   11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO
  263 WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
  264 EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR
  265 OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY
  266 KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
  267 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  268 PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
  269 PROGRAM IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
  270 THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
  271 
  272   12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
  273 WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY
  274 AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU
  275 FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
  276 CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
  277 PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
  278 RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
  279 FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF
  280 SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  281 DAMAGES.
  282 
  283 		     END OF TERMS AND CONDITIONS
  284 
  285 	    How to Apply These Terms to Your New Programs
  286 
  287   If you develop a new program, and you want it to be of the greatest
  288 possible use to the public, the best way to achieve this is to make it
  289 free software which everyone can redistribute and change under these
  290 terms.
  291 
  292   To do so, attach the following notices to the program.  It is safest
  293 to attach them to the start of each source file to most effectively
  294 convey the exclusion of warranty; and each file should have at least
  295 the "copyright" line and a pointer to where the full notice is found.
  296 
  297     <one line to give the program's name and a brief idea of what it does.>
  298     Copyright (C) <year>  <name of author>
  299 
  300     This program is free software; you can redistribute it and/or modify
  301     it under the terms of the GNU General Public License as published by
  302     the Free Software Foundation; either version 2 of the License, or
  303     (at your option) any later version.
  304 
  305     This program is distributed in the hope that it will be useful,
  306     but WITHOUT ANY WARRANTY; without even the implied warranty of
  307     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  308     GNU General Public License for more details.
  309 
  310     You should have received a copy of the GNU General Public License
  311     along with this program; if not, write to the Free Software
  312     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  313 
  314 
  315 Also add information on how to contact you by electronic and paper mail.
  316 
  317 If the program is interactive, make it output a short notice like this
  318 when it starts in an interactive mode:
  319 
  320     Gnomovision version 69, Copyright (C) year name of author
  321     Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
  322     This is free software, and you are welcome to redistribute it
  323     under certain conditions; type `show c' for details.
  324 
  325 The hypothetical commands `show w' and `show c' should show the appropriate
  326 parts of the General Public License.  Of course, the commands you use may
  327 be called something other than `show w' and `show c'; they could even be
  328 mouse-clicks or menu items--whatever suits your program.
  329 
  330 You should also get your employer (if you work as a programmer) or your
  331 school, if any, to sign a "copyright disclaimer" for the program, if
  332 necessary.  Here is a sample; alter the names:
  333 
  334   Yoyodyne, Inc., hereby disclaims all copyright interest in the program
  335   `Gnomovision' (which makes passes at compilers) written by James Hacker.
  336 
  337   <signature of Ty Coon>, 1 April 1989
  338   Ty Coon, President of Vice
  339 
  340 This General Public License does not permit incorporating your program into
  341 proprietary programs.  If your program is a subroutine library, you may
  342 consider it more useful to permit linking proprietary applications with the
  343 library.  If this is what you want to do, use the GNU Library General
  344 Public License instead of this License.