Allow bypassing Kubernetes start

Provide a 'kubernetes' flag that allows you to connect to a Kubernetes
apiserver for pods and clients.  Currently requires your Kube cluster
to be unprotected.  You may also want to specify 'etcd' to use the
Kubernetes etcd server.

    openshift start --kubernetes=otherserver --etcd=otherserver master
Merge pull request #236 from smarterclayton/make_kube_optional

Merged by openshift-bot