* bus/bus.c (bus_context_new): print the address in here, rather
	than in main(), because we need to do it before forking the daemon

	* bus/dispatch.c (send_service_nonexistent_error): set the sender
	on the service nonexistent error

	* bus/driver.c (bus_driver_handle_acquire_service): set the
	sender on the AcquireService reply

	* test/data/valid-config-files/debug-allow-all.conf.in: Make test
	server also listen on a UNIX socket so services can connect to it.