Changes:
- Touched up on Event some more
- Added EventModel for storing/retrieving events
- Added the controllers and requestobservers for transmitting events with a server
- Added the EventEntityManager for server side functionality of events
- Added tests for Event, EventModel, and EventEntityManager
Merge branch 'dev' of https://github.com/tomorrow-nf/wpi-suite-team5 into dev

Additional Changes:
- Fixed an issue with CategoryTest trying to convert toJSon and fromJson with an Event
- Added EventEntityManager to ManagerLayer