Make select_all not work if you're in SINGLE mode (it doesn't make that

Make select_all not work if you're in SINGLE mode (it doesn't make that

Fri Mar  9 20:36:21 2001  Jonathan Blandford  <jrb@redhat.com>

	* gtk/gtktreeselection.c (gtk_tree_selection_select_all): Make
	select_all not work if you're in SINGLE mode (it doesn't make that
	much sense, anyway.)

	* gtk/gtktreedatalist.c (_gtk_tree_data_list_node_to_value):
	handle types more sanely.
	(_gtk_tree_data_list_value_to_node): handle types more sanely.
	(_gtk_tree_data_list_node_copy): handle types more sanely.

	* gtk/gtkliststore.c (gtk_list_store_set_cell): fix to work with
	GValue better. Converts the type as well.

	* gtk/gtktreestore.c (gtk_tree_store_set_cell): fix to work with
	GValue better. Converts the type as well.