Author: Mark Nelson
MDL-61764 message_popup: implement privacy provider
http://git.moodle.org/gw?p=moodle.git;a=commit;h=fbf766ba011531614083517d47477deef4448af4
http://github.com/moodle/moodle/commit/fbf766ba011531614083517d47477deef4448af4
+ 3.4 en [privacy:metadata,message_popup]