object ref count cycles, now GladeProject just releases all widgets from the project
	  and keeps a reference to the GladeWidget instead of the GObject, GladeWidget is now
	  GInitiallyUnowned and GladeProject assumes ownership when objects are added to the
	  project (glade-gtk.c in this patch avoids needlessly adding a widget to the project
	  that will be implicitly added, now glade-gtk.c does not directly manually add any
	  widgets to the project).