Better fixes for #3291 and the underlying exdate issues (#3342)

* Worked around several issues in the RRULE library that were causing
deleted calender events to still show, some initial and recurring events
to not show, and some event times to be off an hour. (#3291)
* Renamed variables in *calendarfetcherutils.js* to be more clear about
use of `moment` and js's `Date` class.
* Added calendar config option `forceUseCurrentTime` (default:`false`)
which will ignore overridden `Date.now` in the config in order to keep
some tests consistent.
* Added several unit tests for crossing DST in different timezones with
excluded events.

CHANGELOG.md

@@ -36,6 +36,13 @@ _This release is scheduled to be released on 2024-04-01._
 
 - Unneeded file headers (#3358)
 
+## [2.27.0] - UNRELEASED
+
+### Fixed
+
+- Worked around several issues in the RRULE library that were causing deleted calender events to still show, some
+  initial and recurring events to not show, and some event times to be off an hour. (#3291)
+
 ## [2.26.0] - 01-01-2024
 
 Thanks to: @bnitkin, @bugsounet, @dependabot, @jkriegshauser, @kaennchenstruggle, @KristjanESPERANTO and @Ybbet.