* sec_acl.cc (getacl): Check ace_sid == well_known_world_sid

	* sec_acl.cc (getacl): Check ace_sid == well_known_world_sid
	before owner_sid and group_sid so that well_known_world_sid
	means "other" even when owner_sid and/or group_sid are Everyone.
	* security.cc (get_attribute_from_acl): Created from code common
	to get_nt_attribute() and get_nt_object_attribute(), with same
	reordering as in getacl() above.
	(get_nt_attribute): Call get_attribute_from_acl().
	(get_nt_object_attribute): Ditto.