[gtk2-perl-xs] first pass at GladeXML added

[Ross McFarland <rwmcfa1 neces com>]

a first pass at GladeXML has been added. it will work, but much of the
callback stuff (outside of signal_autoconnect) hasn't been added. a
slightly modified version of one of the libglade examples is tested. i
don't know much about libglade so others should probably test it out if
they do.

i'll probably try getting all of the callback stuff going sometime
tomorrow. 

next on the list is GtkHTML i'll let the list know if/when that happens.

-rm