manifest: And enable docker-storage-setup by default
cloud: Switch to new LVM partitioning

Here we have a 300MB /boot, 3G for the OS, and the rest will go to
Docker containers.  This allows for a "direct LVM" model; see:

http://developerblog.redhat.com/2014/09/30/overview-storage-scalability-docker/
vagrant: Really disable cloud-init