Chmod the right file in cluster/vagrant/util.sh

Most of platforms use ~/.kubernetes_auth, but Vagrant is different.
This commit fixes one instance where a setup script did not take this
difference into account.
Merge pull request #2430 from rlarocque2/vagrant_auth_fix

Chmod the right file in cluster/vagrant/util.sh
update AWS for the 0.5 release.
Implements a credentialprovider library for use by DockerPuller.

This change refactors the way Kubelet's DockerPuller handles the docker config credentials to utilize a new credentialprovider library.

The credentialprovider library is based on several of the files from the Kubelet's dockertools directory, but supports a new pluggable model for retrieving a .dockercfg-compatible JSON blob with credentials.

With this change, the Kubelet will lazily ask for the docker config from a set of DockerConfigProvider extensions each time it needs a credential.

This change provides common implementations of DockerConfigProvider for:
 - "Default": load .dockercfg from disk
 - "Caching": wraps another provider in a cache that expires after a pre-specified lifetime.

GCP-only:
 - "google-dockercfg": reads a .dockercfg from a GCE instance's metadata
 - "google-dockercfg-url": reads a .dockercfg from a URL specified in a GCE instance's metadata.
 - "google-container-registry": reads an access token from GCE metadata into a password field.
Some small aws refinements.
Merge pull request #2409 from mattmoor/master

Implements a credentialprovider library for use by DockerPuller.
Remove deprecated nsinit from the node definition.
Merge pull request #2436 from brendandburns/salt

Remove deprecated nsinit from the node definition.
Kubelet talks securely to apiserver.

Configure apiserver to serve Securely on port 6443.
Generate token for kubelets during master VM startup.
Put token into file apiserver can get and another file the kubelets can get.
Added e2e test.
Don't reference non-existent token file if not GCE.
Only test events on GCE.