Author: Mihail Geshoski
MDL-65956 mod_assign: Add proper capability checks and error handling
http://git.moodle.org/gw?p=moodle.git;a=commit;h=49953fd4cadad9fbfee0cf0bdf7970bb390532a5
http://github.com/moodle/moodle/commit/49953fd4cadad9fbfee0cf0bdf7970bb390532a5
+ 3.7 en [usersubmissioncannotberemoved,mod_assign]