* src/glade-builtins.c: stock spec name fixed and removed construct only.

	* src/glade-property.c:
	  - Fixed glade_property_dup () to use properties.
	  - Fixed double free in glade_property_finalize (thankyou valgrind)

	* src/main.c: Removed workaround for an old fixed bug in gtk+, no reason to have
	  obscure code like that when we are targeting a recent version of gtk+.

	* widgets/gtk+.xml: Ignore selectable changes & implement ignore property

	* src/glade-property-class.c, src/glade-property.[ch]: implement ignore