Author: Damien Bezborodov
MDL-45678 assignsubmission_comments: Improve performance for permissions checking
http://git.moodle.org/gw?p=moodle.git;a=commit;h=0ba5f02b15f467700de0c9407c3cd0cd65692b1c
http://github.com/moodle/moodle/commit/0ba5f02b15f467700de0c9407c3cd0cd65692b1c
+ 2.7 en [cachedef_get_suspended_userids,core_cache]