recalculating only the new hanchans shoud do the trick now.

the racalc cronjob reports erronous partly recalculations now.
A lot of code cleanups

src/events/mixins.py

@@ -39,5 +39,4 @@ class EventDetailMixin(object):
             context['event'] = self.object
         elif hasattr(self, 'object') and hasattr(self.object, 'event'):
             context['event'] = self.object.event
-        print(context)
         return context