* test/test-utils.c: use dispatch status function to fix this up

	* bus/connection.c (connection_watch_callback): don't dispatch
	from here
	(connection_timeout_callback): don't dispatch from here
	(bus_connections_setup_connection): set the dispatch status function
	(bus_connection_disconnected): unset it

	* dbus/dbus-mainloop.c (_dbus_loop_queue_dispatch): new function
	used to add a connection to be dispatched
	(_dbus_loop_iterate): do the dispatching at the end of each
	iteration

	* dbus/dbus-connection.c
	(dbus_connection_set_dispatch_status_function): new function
	allowing us to fix up main loop usage
	(_dbus_connection_last_unref): free all the various function
	user data
	(dbus_connection_dispatch): call the DispatchStatusFunction
	whenever this function returns
	(dbus_connection_handle_watch): call DispatchStatusFunction
	(dbus_connection_send_with_reply_and_block): call DispatchStatusFunction
	(reply_handler_timeout): call DispatchStatusFunction
	(dbus_connection_flush): call DispatchStatusFunction