* lib/exitcodes.h: Define E_SUCCESS as EXIT_SUCCESS. Added FIXMEs.

	* lib/exitcodes.h: Define E_SUCCESS as EXIT_SUCCESS. Added FIXMEs.
	* libmisc/chowntty.c, libmisc/rlogin.c, libmisc/sub.c,
	src/newusers.c, libmisc/sulog.c, libmisc/system.c, src/logoutd.c,
	src/groups.c, src/id.c, lib/encrypt.c, libmisc/audit_help.c,
	libmisc/limits.c: Return EXIT_FAILURE instead of 1, and
	EXIT_SUCCESS instead of 0.
	* libmisc/audit_help.c: Replace an fprintf() by fputs().
	* libmisc/audit_help.c: Remove documentation of the audit_logger
	returned values. The function returns void.
	* libmisc/system.c: Only return status if waitpid succeeded.
	Return -1 otherwise.