* plugins/gtk+/gtk+.xml.in: Filled in all since, deprecated and
	  builder-unsupported properties.

	* gladeui/glade-widget.c, gladeui/glade-widget.h, gladeui/glade-widget-adaptor.c,
	gladeui/glade-command.c, gladeui/glade-widget-adaptor.h,
	gladeui/glade-utils.h, gladeui/glade-catalog.c, 
	gladeui/glade-catalog.h, gladeui/glade-app.c, gladeui/glade-app.h, 
	gladeui/glade-property-class.c, gladeui/glade-property-class.h, 
	gladeui/glade-project.c, gladeui/glade-project.h:
	Added versioning support, you can always chose the target version of
	your project starting with gtk+ 2.8 - a project preferences dialog has
	been added where you can switch your format, switch your target version
	and test for incompatabilities. incompatability error dialogs are also
	launched on save as. Target versions are saved to the glade file; 
	TODO: patch GtkBuilder to test the required gtk+ version from
	<requires lib="gtk+" version="2.8"> and at least warn,...