Revision 3171

Improved the Real(), Complex(), Point(), Vector(), Matrix() and
String() constructors so that they will process formulas passed to
them as strings rather than requiring perl objects for these.

For example, you can use Real("2/3") rather than Real(2/3) if you
want.  Also, Real("1+x") will return a formula returning a real
(essentially the same as Formula("1+x") in this case).