Fix deployment of local backends
Start cinder-volume service after having created additional config files
Restart cinder-volume when /etc/cinder/cinder_emc_config-*.xml change
Validate that there's no duplicate volume name in proposal
Make boot.looplvm support multiple loop devices
Validate that nodes have enough disks for all raw backends

This doesn't take into account the fact that some backends might request
all disks, but that's good enough for now.
Only allow selecting one disk when using multiple raw devices
Avoid duplicate chef resources for local/raw backends

Also make logs a bit more explicit
Validate that local backends don't use the same file name
Cleanup call to methods for local/raw backend setup
Allow using different ceph deployments for ceph backends

There can be only one Ceph deployed by Crowbar, but other deployments
can also be used.
Use correct attribute: backend_driver, not volume_driver
Merge pull request #1 from vuntz/multi_backend

Fixes for multi-backend