Make "kubecfg -s <port> run ..." select correctly

kubecfg run creates a replication controller which sets all pods with a
replicationController= label, but then sets up a service selecting on name=
instead.  This fixes that.  kubecfg -s <port> run ... can now actually work.
Fair port. The service is optional. Unfortunately, it's also weird for the service to carry a replicationController label. We should choose a term that doesn't overlap with system objects.

How about kubecfgRun?