2006-04-25  Elijah Newren  <newren gmail com>

	Clear _NET_WM_VISIBLE_NAME (and the ICON_ equivalent) when no
	longer being used.  Fixes #330671.

	* src/window.[ch] (struct MetaWindow): new
	using_net_wm_visible_name and using_net_wm_visible_icon_name bits,
	(meta_window_new_with_attrs): initialize these new bits to false

	* src/window-props.c (set_title_text, set_window_title, set_icon_title):
	if the _NET_WM_VISIBLE_(ICON_)NAME property was previously set but
	doesn't need to be this time, make sure to clear it