Author: Shamim Rezaie
MDL-62318 core_group: Add implementation of privacy API
http://git.moodle.org/gw?p=moodle.git;a=commit;h=bc36eb358c9fe662b04181c59a54982e8231adb7
http://github.com/moodle/moodle/commit/bc36eb358c9fe662b04181c59a54982e8231adb7
+ 3.4 en [privacy:metadata:groups,core_group]
+ 3.4 en [privacy:metadata:groups:groupid,core_group]
+ 3.4 en [privacy:metadata:groups:timeadded,core_group]
+ 3.4 en [privacy:metadata:groups:userid,core_group]