Add ExtractList to runtime.
Add healthz handlers to the controller manager and scheduler
Merge pull request #1306 from lavalamp/scheduler

Add ExtractList to runtime.
Merge pull request #1296 from brendandburns/healthz

Add healthz handlers to the controller manager and scheduler
apiserver does not require a cloud provider or machine list

Currently the apiserver will not start unless a machine list or a
valid cloud provider is specified. This prevents a workflow that
manages machines solely through the minions API.

Fix the issue by changing the apiserver to only log a message that
the apiserver is being started with an empty machine list.

This patch results in a change in behavior. The apiserver will no
longer exit non-zero if a cloud provider or machine list is not
configured.
Merge pull request #1320 from kelseyhightower/run-without-machines

apiserver does not require a cloud provider or machine list
Make needed changes in conversion package to support pluggability
pkg/runtime now has a well defined api pluggability model.
Fixes:

* Fix kubecfg test, which was writing an internal object straight to yaml
* Address review comments
add PluginBase to fuzz functions
Remove custom scheme stuff

As separate commit to make it easy to get back-- I'm not completely
convince we won't want this in the future.
Merge pull request #1239 from lavalamp/fixApi

Proposal for solving api plugability
Fix leaking FD.