Similar to the "New Event Notification" plugin, please also create the "Event Edit Notification" plugin. This should take only a few minutes and you could use the existing onEventChangeState trigger. It will be so much helpful to us.
Also, in addition to the user-groups selection feature, please also have a new field called "comma separated email addresses" where the emails will be sent. Most of the times, we don't need to send the email to ALL the users in a group, but only to specific email addresses.
