Update commands to reflect latest changes.
Fixes golint errors in pkg/health
Fixes golint errors in pkg/healthz
Rename a function according to go convention
Correct godoc messages according to review comments
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.
Retrieve machine spec from cAdvisor
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.
Merge pull request #491 from monnand/cadvisor-update-3

Retrieve machine spec from cAdvisor
fix typo
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.
Merge pull request #287 from rafael/patch-1

Update commands to reflect latest changes.
Merge pull request #487 from yugui/fix/golint

Fixes Go lint errors and a style fix
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.