Keep a list of tasks that don't belong to any class group. Fix bug

2007-07-07  Vincent Untz  <vuntz@gnome.org>

	Keep a list of tasks that don't belong to any class group.
	Fix bug #453777. And complete fix for bug #165075.

	* libwnck/tasklist.c: (wnck_tasklist_init): initialize new
	windows_without_class_group field.
	(wnck_tasklist_finalize): add new assertion
	(wnck_tasklist_size_allocate): append the tasks from
	windows_without_class_group to the list of visible tasks
	(wnck_tasklist_remove): remove the task from
	windows_without_class_group when it's needed
	(wnck_tasklist_free_tasks): add assertion
	(wnck_tasklist_update_lists): if there's no class group for the
	window, add it to windows_without_class_group

svn path=/trunk/; revision=1394