* check-signals.pl: Wrote a script to check for people who forget
	to call gtk_object_class_add_signals. It found only one violation,
	and that was already fixed by the time I got around to checking
	this in.

	* libnautilus-extensions/nautilus-directory-async.c:
	(get_info_callback): Added a code to check the error result from
	get_file_info. Without this, we were doing

	* src/nautilus-sidebar-title.c: (nautilus_sidebar_title_set_uri):
	Fixed it so we won't destroy and then instantly recreate the same
	NautilusFile if the URI is set to the same value.