Author: Ankit Agarwal
MDL-32431 backup: Adding the feature to support backing up and restoring calendar events
http://git.moodle.org/gw?p=moodle.git;a=commit;h=79cbfaa114886a03b11bd46560c5b58aeb597be9
http://github.com/moodle/moodle/commit/79cbfaa114886a03b11bd46560c5b58aeb597be9
+ 2.1 en [rootsettingcalendarevents,core_backup]