[WIP] Add support for Config{} to kubecfg

This PR will allow users to use simple JSON file with arrays of Kubernetes objects (services, pods, replicationControllers) as a parameter for `kubecfg -c config.json apply` command.

The [example JSON](https://github.com/mfojtik/kubernetes/blob/config/examples/config/guestbook.json) file in `examples/config/guestbook.json` contains all objects required for deploying the [guestbook example](https://github.com/GoogleCloudPlatform/kubernetes/tree/master/examples/guestbook).
I think for now it is probably sufficient to start the services first (as Brian suggests below). Starting the service will cause the appropriate environment variables to get set, even if the service isn't live yet; users of the service would have to retry if it's not up yet.