Author: Mark Nelson
MDL-63211 core: added notification when contact request is made
http://git.moodle.org/gw?p=moodle.git;a=commit;h=be016b0144ce41e37bf3ed146bcf02780d148030
http://github.com/moodle/moodle/commit/be016b0144ce41e37bf3ed146bcf02780d148030
+ 3.6 en [messagecontactrequestsnotification,core_message]
+ 3.6 en [messagecontactrequestsnotificationsubject,core_message]
+ 3.6 en [messageprovider:messagecontactrequests,core]