Author: Shamim Rezaie
MDL-61115 mod_lesson: Lesson overrides to observe group membership
http://git.moodle.org/gw?p=moodle.git;a=commit;h=1aa9422c9f76bef3fb6499d21024c30c981c3a20
http://github.com/moodle/moodle/commit/1aa9422c9f76bef3fb6499d21024c30c981c3a20
+ 3.6 en [groupsnone,mod_lesson]