New acinclude.m4

Attached is a new acinclude.m4, and a patch to our current acinclude,
that relies on wx-config for all the flags. Gone is all the
complicated stuff. The only thing this new acinclude doesn't do is
warn about a missing stc or ogl. It will link against them, but if a
user doesn't have them, their compile will fail. I'll be adding in
stub programs to test for this in my next version. In the meantime,
test and enjoy.

On another note, could someone please check out ./pkg/mac/complete-
bundle.sh and chmod +x it? The compile on mac fails with an error
because the execute bit is not set.

ahp