Make G_CONST_RETURN.

Make G_CONST_RETURN.

Thu Mar  8 00:02:30 2001  Owen Taylor  <otaylor@redhat.com>

	* gtk/gtkwidget.[ch] (gtk_widget_get_name): Make
	G_CONST_RETURN.

	* gtk/gtkwidget.[ch] gtk/gtkprivate.h: Add a
	::hierarchy-changed signal when a widget changes
	from anchored to unanchored or vice versa.
	(anchored means
	 gtk_widget_get_ancestor (widget, GTK_TYPE_WINDOW) != NULL.)
	Use a private flag to keep track of this efficiently.