add getter/setter for show-expanders property, queue a redraw when this

add getter/setter for show-expanders property, queue a redraw when this

2006-10-08  Kristian Rietveld  <kris@gtk.org>

	* gtk/gtktreeview.[ch] (gtk_tree_view_set_property),
	(gtk_tree_view_set_show_expanders),
	(gtk_tree_view_get_show_expanders): add getter/setter for
	show-expanders property, queue a redraw when this property
	is toggled (#351167, Martin Ejdestig),
	(gtk_tree_view_set_level_indentation),
	(gtk_tree_view_get_level_indentation): also add getter/setter
	and docs for level-indentation property.