Allow the specification of adding in a graceperiod when deleting a pod.

I0426 20:11:04.234863 5326 request.go:579] Request Body:

{"kind":"DeleteOptions","apiVersion":"v1","gracePeriodSeconds":6}

I0426 20:11:04.235062 5326 round_trippers.go:264] DELETE https://172.28.128.4:8443/api/v1/namespaces/fromimage/pods/nodejs-1-p2b2u

ref: Godeps/_workspace/src/k8s.io/kubernetes/pkg/api/v1/types.go