cyclades: Add dummy management commands for volumes
cyclades: Allow snapshots only for ext_ template
Do not allow taking a snapshot from a volume, if the disk template isnot ext_*.
cyclades: Various fixes for volumes and snapshots
cyclades: Initialize 'volume' app
Initialize new 'volume' app, which will implement the block storage APIof Cyclades.
cyclades: Add urls for volume API
cyclades: Implementat volumes and snapshots
cyclades: Add tests for volumes