Author: Ankit Agarwal
MDL-42079 calendar: Update core apis to support ical imports with rrule repeats
http://git.moodle.org/gw?p=moodle.git;a=commit;h=0f1e1313a5d3980d5d500c2567f7b6942f1be19a
http://github.com/moodle/moodle/commit/0f1e1313a5d3980d5d500c2567f7b6942f1be19a
+ 2.7 en [errorrrule,core_calendar]
+ 2.7 en [errorrrulefreq,core_calendar]
+ 2.7 en [errorrruleday,core_calendar]