if john is the organizer and has the shared folders of jane, john can accept on behalf of jane by simply changing the status in the incidenceeditor.
* An update email is sent to jane (who isn't the organizer). This is probably correct in our responsibility as organizer to keep participants up to date.
* No email is sent to john, meaning john's copy of the event becomes outdated and john therefore never sees the updated status of jane on the event.