#XEmacs 21 now supports Imenu, so I am able to test (and fix) some

#simple things.  First step: rename the Imenu supportive variables and
#functions in this file to py-imenu-* so I can grok what is part of
#python-mode and what is part of Imenu.

(py-imenu-create-index-engine): Fixed problem with two classes in a
single file, caused by new semantics of py-beginning-of-def-or-class
when called programmatically.

#Note, there are still some problems with Imenu when arguments to
#functions are funky, but it should be much better now.