Got rid of GtkTreeNode, and changed it to GtkTreeIter. Added iterators

Got rid of GtkTreeNode, and changed it to GtkTreeIter. Added iterators

Wed Oct 25 20:40:25 2000  Jonathan Blandford  <jrb@redhat.com>

	* gtk/gtktreemodel.h: Got rid of GtkTreeNode, and changed it to
	GtkTreeIter.  Added iterators everywhere.

	* gtk/gtktreeviewcolumn.c: Changed to use the iterators.

	* gtk/gtktreeviewselection.c: Changed to use the iterators.

	* gtk/gtktreestore.c: Changed to use the iterators.

	* gtk/gtkliststore.c: Commented out the code.  Will convert to
	iterators tomorrow.

	* gtk/gtkmodelsimple.c: Commented out the code.  Will convert to
	iterators tomorrow.

	* gtk/treestoretest.c: Changed to use iterators.

	* demos/testgtk/main.c: Moved to use the new iterator system.