Separate hpcloud v12 and v13

Separates hpcloud v12 support out (v13 is superceding it and is closer to openstack). Currently requires provider to be specified (hpcloud_v12 or hpcloud_v13). hpcloud will at some point default to latest.

Primarily, patch moves all Diablo/floating IP hacks/weird volume stuff into hpcloud.v12, and hpcloud.v13 is pretty much basic openstack.