Fixes bug that unable to select delete all events option without getting errors in cache rebuilder. Note that this option only deletes events in a primary calendar (a note to this effect has been added). For secondary calendars, calendars have to be manually deleted and then re-created and then re-linked in XenForo.
Fixes bug that cache rebuilder does not allow handlers to be extended, resulting in features from add-ons such as Repeat Events by Waindigo not being able to be applied when the cache is rebuilt.
Added new 'Edit default Google calendars' permission, allowing specified users to select their own default Google calendars from the front end and have their events posted to their own Google calendar instead.
Added friendly error message for "refresh token" error when setting up Google account authentication.
Added abilty to manage Google Calendars from your Admin Control Panel, allowing you to change the title and description, get the XML/ICAL/HTML for the calendar, set whether the calendar is shared and invite other users to share the calendar.