It would be good to have the following enhancements to the iCAL file that is sent with the registration confirmation email:
(1) Include the QR Code inside the iCAL File so that it would appear inside the calendar of the user's email
(2) When the user adds it to his calendar, if later he updates his calendar about no-more going to attend the event, the website could record the response.
(3) If the user has not responded-yes to the event, the calendar should give them the notification.
