Users Should be Able to Confirm Events

[cycomachead]

I'm submitting a ..

• Bug Report
• Feature Request

Current behavior:
Admins must manually confirm an event.

Expected correct behavior:
Users get an email with a confirm link when an event is accepted.
Admins get an email notifying them that an event has been confirmed.

Steps to reproduce:

Other information:

[cycomachead]

1. Users have an email link to confirm or cancel
2. When a user confirms or cancels, send an email to conf organizers
   • this is auto notification, it should respect the comment notification settings, but email doesn't need to be customizable.
   • include to the event
3. Also send the user an email a confirmation email.
   • this should be editable in the email settings page
   • 1 template for confirm/cancel with variables.