Author: Ankit Kumar Agarwal
MDL-30398 Validations added for password field
http://git.moodle.org/gw?p=moodle.git;a=commit;h=6fe2462f989ff52655ba3303c9a7a4c3d26ab81c
http://github.com/moodle/moodle/commit/6fe2462f989ff52655ba3303c9a7a4c3d26ab81c
+ 2.1 en [emptypassword,mod_lesson]