Revision 956

Added the capability to the GlobalTableEmulator to designate a user
whose records will be used as global records. To specify this, set the
globalUserID param for the tables using the GlobalTableEmulator (in
%dbLayout). It's probably good to do this on a per-course basis. Put the
following in your course.conf:

	$dbLayout{set}->{params}->{globalUserID} = "professor";
	$dbLayout{problem}->{params}->{globalUserID} = "professor";

If globalUserID is not present, GlobalTableEmulator will use consensus
(which is very slow!).
-sam