Adds initial volumes package; Supports host-dirs

Adds the framework for external volume mounts.

Currently supports bare host directory mounts.

Modifies the API to support host directory mounts from Volumes
instead of VolumeMounts.
Adds EmptyDirectory volume struct

Adds EmptyDirectory to volumes. This represents a directory
on the host, given to a pod that should not persist beyond.

The current draft does not cleanup after itself.
API modified to use source; now supports EmptyDirectory

API is now modified to use a Source struct to handle multiple volumes.

Two volume types are supported now, HostDirectory and EmptyDirectory.
Make RESTful operations return 404 Not Found when the target resource
does not exist.

In the original implementation, GET, DELETE and PUT operations on
non-existent resources used to return 500 but not 404.
Remove some verbose logging
Merge pull request #511 from smarterclayton/remove_excess_logging

Remove some verbose logging
Merge pull request #486 from yugui/fix/404-if-notfound

Make RESTful operations return 404 Not Found when the target resource does not exist.
Insert a couple of sleeps to slow things down.
Merge pull request #514 from brendandburns/fix

Insert a couple of sleeps to slow things down.
Add some more logging to service updates.
Operation server was not returning in error cases
Turn off error checking prior to sanity checking.
Merge pull request #516 from smarterclayton/operation_server_not_returning

Operation server was not returning in error cases
kubelet: cleanup
Merge pull request #515 from brendandburns/fix

Add some more logging to service updates.
Merge pull request #517 from brendandburns/sanity

Turn off error checking prior to sanity checking.
Merge pull request #509 from xiangli-cmu/kubelet

kubelet: cleanup
PodInfo should indicate when a pod is not found

Client should react.  Also, dial down the chattiness of errors for
pods which do not exist and stop processing NotFound earlier in
the podinfo chain
Make build-release.sh not directory dependant.
Merge pull request #518 from MSOpenTech/shell-scripts

Make build-release.sh not directory dependant.