move the initialization of the addresses in the plugin interface
structure from run-time to link time;
don't attempt to rebuild the X* files automatically, just warn
that they're out of date and show the command used to rebuild
them (not everybody has GCC installed, but it's required in
order to rebuild them).
Get rid of the checked-in Xepan_plugins.c, as it's no longer generated
or used.
Fix Makefile.am now that Xepan_plugins.c has been replaced by Xass-list.
Give plugin_gen.py an RCS ID.
svn path=/trunk/; revision=8186
