include bugs in gnome2 modules

[Frank Belew <frb ximian com>]

I've noticed quite a few gnome2 modules have hardcoded in their
Makefile.am in INCLUDES a -I$(includedir)
This breaks if your gnome1 prefix == gnome2 prefix since it will find
headers there first. Since all the gnome deps are managed by pkg-config
and everything else is in system direcrories, this is unnecessary. If
you have a dep that isn't in a standard place, then the builder must use
CPPFLAGS

In other words, don't add -I$(includedir) to your INCLUDES, it causes
too many problems.


-- 
Frank