* bus/loop.c (bus_loop_iterate): fix the timeout code, using
	magic from GLib

	* dbus/dbus-spawn.c (_dbus_babysitter_unref): set sitter_pid
	to -1 once we've reaped the babysitter
	(_dbus_babysitter_handle_watch): do as much work as we can, not
	just one go of it

	* bus/activation.c: add code using DBusBabysitter so that we
	handle it when a service fails to start up properly.
	(bus_activation_service_created): don't remove the activation
	entries as we go, just let them get removed when we free the pending
	activation. Unref reply messages after sending them.