Considerably speed up GtkUIManager, by changing the semantics of the dirty

Considerably speed up GtkUIManager, by changing the semantics of the dirty

2004-11-11  Matthias Clasen  <mclasen@redhat.com>

	Considerably speed up GtkUIManager, by changing the semantics
	of the dirty flag. It is now propagated up the tree, and
	update_node() doesn't descend into clean subtrees.  (#143668,
	Dave Neary, Michael Natterer, Sven Neumann, fix proposed
	by Soeren Sandmann)

	* gtk/gtkuimanager.c (node_prepend_ui_reference): Only prepend
	a new node reference if the merge_id is different. Take a GNode,
	so we can walk up the tree, adjust all callers.
	(node_remove_ui_reference): Only mark a node dirty if the first
	ui reference is removed. Take a GNode here as well for
	consistency.
	(update_node): Don't descend into clean subtrees.
	(mark_node_dirty): New function to mark a node and its
	predecessors dirty.