Author: Arnaud Trouve
MDL-53044 auth : force change on expired password
http://git.moodle.org/gw?p=moodle.git;a=commit;h=9de4bbf8a8023421f74dba1013f7b990e0e69ad3
http://github.com/moodle/moodle/commit/9de4bbf8a8023421f74dba1013f7b990e0e69ad3
+ 3.2 en [auth_passwordisexpired,core_auth]