Author: Andrew Nicols
MDL-68442 user: Add notifications on unenrol/update
http://git.moodle.org/gw?p=moodle.git;a=commit;h=829f86032157aa01aa87eb7828e52b453dc84f8b
http://github.com/moodle/moodle/commit/829f86032157aa01aa87eb7828e52b453dc84f8b
+ 3.9 en [enrolmentupdatedforuser,core_enrol]
+ 3.9 en [unenrolleduser,core_enrol]