Author: Jun Pataleta
MDL-57658 calendar: Fix rrulemanager and unit tests
Issues fixed:
* Additional rule validations.
* Rewrote recurrence logic.
* Additional unit tests, especially from the examples in the RFC.
* The date format "YmdThis" results into an incorrect date for the
"UNTIL" parameter. The literal "T" should be escaped, and a literal
"Z" is also needed at the end of the format string to indicate UTC.
* Implemented handling of negative modifier values for BYxxx rules.
* Implemented handling of BYWEEKNO, BYYEARDAY, BYSETPOS, BYHOUR,
BYMINUTE, BYSECOND rules.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=8ddc656739d3f29464fea448afdd313a9321c7b3
http://github.com/moodle/moodle/commit/8ddc656739d3f29464fea448afdd313a9321c7b3
+ 3.3 en [errorhasuntilandcount,core_calendar]
+ 3.3 en [errorinvalidbydaysuffix,core_calendar]
+ 3.3 en [errorinvalidbydayprefix,core_calendar]
+ 3.3 en [errorinvalidbyhour,core_calendar]
+ 3.3 en [errorinvalidinterval,core_calendar]
+ 3.3 en [errorinvalidbyminute,core_calendar]
+ 3.3 en [errorinvalidbymonth,core_calendar]
+ 3.3 en [errorinvalidbymonthday,core_calendar]
+ 3.3 en [errorinvalidbysetpos,core_calendar]
+ 3.3 en [errorinvalidbyweekno,core_calendar]
+ 3.3 en [errorinvalidbyyearday,core_calendar]
+ 3.3 en [errorinvalidbysecond,core_calendar]
+ 3.3 en [errormustbeusedwithotherbyrule,core_calendar]
+ 3.3 en [errornonyearlyfreqwithbyweekno,core_calendar]