Config generator suite

For #1695.

Takes YAML or JSON of the following form:
```
name: foo
image: busybox
portSpec: 80:8080
```

and spits out a list of API objects (a replication controller and, optionally, a service):
```
- kind: Service
  name: foo
  creationTimestamp: "null"
  port: 80
  labels:
    simpleservice: foo
  selector:
    simpleservice: foo
  containerPort: 8080
- kind: ReplicationController
  name: foo
  creationTimestamp: "null"
  desiredState:
    replicas: 1
    replicaSelector:
      simpleservice: foo
    podTemplate:
      desiredState:
        manifest:
          version: v1beta2
          id: ""
          volumes: []
          containers:
          - name: foo
            image: busybox
            ports:
            - name: main
              containerPort: 8080
            imagePullPolicy: ""
          restartPolicy: {}
      labels:
        simpleservice: foo
  currentState:
    replicas: 0
    podTemplate:
      desiredState:
        manifest:
          version: ""
          id: ""
          volumes: []
          containers: []
          restartPolicy: {}
  labels:
    simpleservice: foo
```

Borrowed lots of code from kubectl, kubecfg, and podex. That code should be organized as a reusable library, but I just copied it for this proof of concept.

This could be invoked as an independent command piping into kubectl or as a build step (#1694), but I'd like to see this as a client tool plugin, conceptually similar to mime-type-based application registration -- when kubectl encountered an object of a non-primitive type, it would invoke the registered transformation pass and then process the output (potentially recursing).

Separately, I also have thoughts about API objects/plugins to handle deployments, but I'd like to get a config generator/plugin example checked in.

/cc @smarterclayton @ghodss @thockin @lavalamp 
Thanks. Ideally most of the functionality in kubectl would be available as libraries for direct programmatic use by clients.

That said, another way to address this particular instance is to add the plugin transformation pipeline framework proposed in https://github.com/GoogleCloudPlatform/kubernetes/issues/1905#issuecomment-60330363, in which case these could be written as routines that take in object streams and return object streams.