* gladeui/glade-xml-utils.h: Added GLADE_TAG_PARENT

	* gladeui/glade-widget-adaptor.c: Made it possible to declare a widget class in the
	  catalog without giving a real type, only automatically derive from a type specified
	  in the catalog (refit Muntyan's patch from bug 352714).


svn path=/trunk/; revision=1517