* src/glade-app.c: Fixed a few compile warnings and fixed signal emmission to
	  use g_signal_emit().

	* src/glade-property.[ch]: glade_property_set to use a va_list for convenience,
	  added glade_property_set_value for setting properties with GValues.
	  Also added emission of value-changed signal.

	* src/glade-command.c, src/glade-editor.c, src/glade-gtk.c, src/glade-widget.c:
	  Changed callers.