Author: Ankit Kumar Agarwal
MDL-30398 Validations added for password field
http://git.moodle.org/gw?p=moodle.git;a=commit;h=7b5abb50ce5f895ae26d57c094232a1c59ef8e09
http://github.com/moodle/moodle/commit/7b5abb50ce5f895ae26d57c094232a1c59ef8e09
+ 2.2 en [emptypassword,mod_lesson]