Events mongo

Events now persist to Mongo.

Am doing this as a pull request as some of the json endpoints have changed (i.e. some of the tool functions are now broken)

The initial page (http://localhost:9000/events) works and loads a list of events.

Endpoints are currently 

POST /events to create a new event
POST /events/the-event-id to update an event
GET /events/the-event-id to get an individual event
GET /events/list to list events by start date (reverse)