JCLOUDS-758 Drop VirtualBox labs provider.
JCLOUDS-292: Added CloudSigma2 ComputeService

* Added the ComputeService implementation
* Added the San Jose region
* Added the Honolulu region
JCLOUDS-750 AutoValue all Docker value types.
Remove tar creation responsibility from docker, avoiding filesystem bias.
JCLOUDS-534 Avoid runtime incompatibility introduced by Guava's closeQuietly.