Author: Shamim Rezaie
MDL-71410 mod_lesson: Cache user and group overrides
http://git.moodle.org/gw?p=moodle.git;a=commit;h=04e6d285d83e41fcbe99959c0c6e27654f99c205
http://github.com/moodle/moodle/commit/04e6d285d83e41fcbe99959c0c6e27654f99c205
+ 3.11 en [cachedef_overrides,mod_lesson]