* bus/bus.c (process_config_every_time):
	don't overwrite existing bus context activation object
	until after we've checked that the new activation is
	valid.

	* bus/main.c
	(signal_handler), (handle_reload_watch):
	don't call exit() on failure, instead make do and keep
	going.
	(close_reload_pipe): new function to turn off
	hangup-causes-config-reload behavior if an unexpected
	error occurs