Author: Mark Nelson
MDL-63211 core: created new events for blocking/unblocking users
http://git.moodle.org/gw?p=moodle.git;a=commit;h=bacebf3738615090da68937b076980e6e96b6cbc
http://github.com/moodle/moodle/commit/bacebf3738615090da68937b076980e6e96b6cbc
+ 3.6 en [eventmessageuserblocked,core_message]
+ 3.6 en [eventmessageuserunblocked,core_message]