updated entity event group subscription logic to not return the super entity
tested that email events are marked as seen when converted
added and tested unsubscription filtering for entity_events
cached the unsubscriptions for unsubscription filtering
coverage
added ability to specify context loaders in the source model
moved the get_context method to the source model
fixed small bug in loading context
removed old unsubscription filtering method from the subscription model
fixed bug in creating event with no actors
coverage
Merge pull request #4 from wesleykendall/develop

Small fixes, mark seen logic, and porting of some old code