Allow Kube proxy to watch for service/endpoint changes

Expose `GET /endpoints/<serviceName>`.  Allow watch on endpoints and with services with `fields=Name%3D<serviceName>`
It does not, client.New handles "127.0.0.1:8080", "http://127.0.0.1:8080", and "http://127.0.0.1" equally.  The default protocol is "http" which as soon as we plumb SSL can then change centrally.