Update salt config for apiserver to support Azure.
Add gce grain to salt config, change apiserver salt config.
Merge pull request #552 from MSOpenTech/azure-scripts

Update salt config for apiserver to support Azure.
Adds a flag to specify root working directory.

--root_dir specifies the directory kubelet will use for it's
procedures. Currently used for volume mounts.
Merge pull request #527 from Sarsate/rootdir-flag

Adds a flag to specify root working directory.
Sync pods asynchronously in the Kubelet.

This makes two main changes:
- Runs syncPod in a separate Go routine (and enforces only one of those
  runs at a time).
- Uses the pod list to determine if a container should be running or
  should be killed (used to use the output of syncPod).

Since Docker pulls are synchronized by the Docker daemon we still block
on that, but pods can now be removed and prepared for starting without
blocking on long pulls.