Added async behavior.
Activate gce minion list.
Merge pull request #293 from brendandburns/minion

Activate cloud minion registry.
Make each pod synchronization async.
Merge pull request #320 from brendandburns/async

Make each pod synchronization in the kubelet an independent thread.
Don't double-close the channel when etcd returns an error.
Merge pull request #325 from lavalamp/etcdChanFix

Don't double-close the channel when etcd returns an error.
Change error printing for easier debugging
Fix interface{} in api/types.go; plumb through system.