Author: Andrew Davis
MDL-37962 core_message:reimplemented the beep on new message functionality from 1.9
http://git.moodle.org/gw?p=moodle.git;a=commit;h=9279cae63b02df86663906e9833813bad9f01380
http://github.com/moodle/moodle/commit/9279cae63b02df86663906e9833813bad9f01380
+ 2.6 en [beepnewmessage,core_message]