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=8dc45b37b7fd8bf30f465ba8043c68b86cef1997
http://github.com/moodle/moodle/commit/8dc45b37b7fd8bf30f465ba8043c68b86cef1997
+ 3.8 en [usersubmissioncannotberemoved,mod_assign]