* bus/activation.c: (bus_activation_service_created),
	(bus_activation_send_pending_auto_activation_messages),
	(bus_activation_activate_service):
	* bus/activation.h:
	* bus/dispatch.c: (bus_dispatch),
	(check_nonexistent_service_auto_activation),
	(check_service_auto_activated),
	(check_segfault_service_auto_activation),
	(check_existent_service_auto_activation), (bus_dispatch_test):
	* bus/driver.c: (bus_driver_handle_activate_service):
	* bus/services.c: (bus_registry_acquire_service):
	* dbus/dbus-message.c: (dbus_message_set_auto_activation),
	(dbus_message_get_auto_activation):
	* dbus/dbus-message.h:
	* dbus/dbus-protocol.h: Implement auto-activation.