Moving EventManager in preparation to decouple it from FileStore.
Devolving event creation to services.
Removing built-in node and event types.

Yes, I'm taking a more JS-like approach for flexibility.
Removing separate node info types and replacing with namespacing.
Replacing NodeInfo with Map<String,String> for extensibility.
Introducing type into server-side flag events.
Fixing tests.
Removing direct access to event info map.
Adding the user who created/removed flag to event info.
Removing deprecation warning - we're testing a deprecated interface.
Adding notifications for edit flag deletion (including forced revokation).
Adding UI option to remove edit flag.
Merge branch 'revoke-flag'. Resolves #92.