Add an implicit node name label for scheduling pods.

This enables easy scheduling to specific nodes, which is a requirement for a "pod per node" controller.

See #1518 
See https://github.com/GoogleCloudPlatform/kubernetes/pull/3021 for the API

To support #1518 we're going to need to write a controller that can take a "schedule-per-pod" object and actively schedule a pod onto each host.

To achieve that, we need the ability to place a pod onto a specific host.

Pseudo-code:

```go
for {
  for _, controller := range perPodControllers {
    for _, node := range currentNodes {
       if podDoesntExist(node, controller.Spec.Template) {
          createPod(node.Name, controller.Spec.Template)
       }
    }
  }
}
```