2006-08-19  Jonathan Matthew  <jonathan@kaolin.wh9.net>

	* shell/rb-shell-player.c: (rb_shell_player_sync_with_source):
	* widgets/rb-header.c: (rb_header_class_init),
	(rb_header_set_property), (rb_header_get_property),
	(rb_header_set_playing_entry), (rb_header_sync),
	(rb_header_sync_time):
	* widgets/rb-header.h:
	Add a 'seekable' property on RBHeader, and use it to make the seek bar
	insensitive when the player backend tells us we can't seek in the
	current song.  From #330410.