Add Event Registry/REST types

This creates an Event-specific backing store.  Presumably there would be a Pod-specific backing store and a Service-specific backing store and an Enpoints-specific backing store and ...

Etcd should be mentioned once in the whole init sequence.  It is the medium.  Then you can define the schemas that sit atop the medium - Event, Pod, Service..

If this isn't clear, maybe it is I who just isn't getting it - come by and we can discuss after lunch?