Author: Mark Nelson
MDL-61764 message_popup: implement privacy provider
http://git.moodle.org/gw?p=moodle.git;a=commit;h=5f02dbb5fdca69536bb1f708c74f9fe489258dd0
http://github.com/moodle/moodle/commit/5f02dbb5fdca69536bb1f708c74f9fe489258dd0
+ 3.3 en [privacy:metadata,message_popup]