JCLOUDS-750 Start using AutoValue on Docker.

this builds on https://github.com/jclouds/jclouds/pull/586 and depends on it.
@nacx fyi I'll update this PR with the case format from the latest api. Also, I will look at using the SerializedNames annotation for serialization, too. It isn't as easy to get as it was for deserialization, but not impossible.