Add a type check to the values being compared when iterating over
current and changed values in a calendar event. Also, rewrite to use
dictionary comprehension for readability.
Exception handling was also changed to only log the errors rather
than to raise them to the user, since the sync is run as a cron
and that we want other calendars to be polled if one fails.
- Properly synchronize the timezone for users with timezones set in Odoo
- Properly synchronize attendees, i.e. remove the organizer from the
attendees list on the CalDAV server and re-add them on the event
attendees in Odoo (to show up in the calendar view).
