dav_events: added fields to the Event.as_dict() method

- deadline_expired
- canceled

dav_events/models/event.py

@@ -579,6 +579,8 @@ class Event(models.Model):
             'registration_required': self.registration_required,
             'registration_howto': self.registration_howto,
             'deadline': self.deadline,
+            'deadline_expired': self.is_deadline_expired(),
+            'canceled': self.is_canceled(),
             'registration_closed': self.registration_closed,
 
             'charge': self.charge,