Fix typo
Switched Broker to using Moose
EventBuilder now implemented via Moose
Switched EventNormalizer to Moose
Merge EventNormalizer into EventBuilder
Remove severity map

- This kind of mapping should be done when feeds are generated or when
  data is queried. Not on the front end.
Make assessment required for building an Event.
Removing legacy upgrade code
Enforce UUID format on guid/id for Event
Remove redundant information

- Removed 'guid' from Submission. It's already on Event.
- Removed 'data' from DBI plugins. Everything needed is contained within
  Event.