API for broker-to-subscribers #7

Formulate the subscriber API version .1 This should include authentication/nonce bits for setting up the connection. It should also include a set of event types that are relevant to advertising set of system events to the client. Roughly this include the same set of events as in the publisher API: NewEvent, ProcessJoined, ProcessLeft,

A complete API would need to be specified as a JSON RPC set of method calls, and an example client (in Go, or JS) that would interface with the server-side API.