fix omitempty on PodSpec.ServiceAccount in v1beta3

bump the ubuntu k8s version to 0.18.0

Align systemd environ file with optimal admission controllers

Fixes panic/nil pointer in PV

Fix guestbook example based on hackathon feedback.

minor cleanup for apiserver/errors.go

Gracefully delete pods from the Kubelet

gke provider: Fix "gcloud .* describe" checks in util.sh

Disabled load e2e test for scalability Jenkins job

This basically prevents you from re-running e2es cross-project on the
GKE provider. (The current Jenkins jobs that have been moved to
different projects are working kind of accidentally.)

Check Spec.PersistentVolumeSource in NFS, RBD, Gluster and iSCSI volume
plugins.

Retry downloading binary tars in case of unpack failure

Re-enabled load e2e test for Jenkins scalability suite

Also increased next pod startup waiting time from 100s to 200s
to eliminate flakiness by incresing failCount param.

Use watch-based cache in density e2e tests.

coreos/azure: Version bump and doc update

Added note about AWS env variable to specify location of private key

Pods that are slated for deletion should be excluded from
replication and endpoints immediately.

This commit wires together the graceful delete option for pods
on the Kubelet.  When a pod is deleted on the API server, a
grace period is calculated that is based on the
Pod.Spec.TerminationGracePeriodInSeconds, the user's provided grace
period, or a default.  The grace period can only shrink once set.
The value provided by the user (or the default) is set onto metadata
as DeletionGracePeriod.

When the Kubelet sees a pod with DeletionTimestamp set, it uses the
value of ObjectMeta.GracePeriodSeconds as the grace period
sent to Docker.  When updating status, if the pod has DeletionTimestamp
set and all containers are terminated, the Kubelet will update the
status one last time and then invoke Delete(pod, grace: 0) to
clean up the pod immediately.

Fix kubectl run broken at HEAD

docs: markdown and simple fixes

e2e: Specify RestartPolicy=Never in empty_dir test

Refactored kube-push.sh script

GCE kube-down.sh error fixes

Fix cluster monitoring setup config.

Soak ns 2