Author: Arnaud Trouve
MDL-53044 auth : force change on expired password
http://git.moodle.org/gw?p=moodle.git;a=commit;h=723a9dd9f45829f94e23c85d1586688d2d58d715
http://github.com/moodle/moodle/commit/723a9dd9f45829f94e23c85d1586688d2d58d715
+ 3.3 en [auth_passwordisexpired,core_auth]