remove gtk_tree_model_get_first in favor of gtk_tree_model_get_iter_root.

remove gtk_tree_model_get_first in favor of gtk_tree_model_get_iter_root.

Mon Jul  9 12:50:51 2001  Jonathan Blandford  <jrb@redhat.com>

	* gtk/gtktreemodel.c: remove gtk_tree_model_get_first in favor of
	gtk_tree_model_get_iter_root.

	* gtk/gtkliststore.c: Add a bunch of g_return statements.
	(gtk_list_store_iter_n_children): Fix up.

	* gtk/gtktreestore.c: Add a bunch of g_return statements.