Feature #2568: Support for RBD Format 2 images
Feature #2568: Refactor RBD2 format contribution by Bill Campbell:

- Use BRIDGE_LIST instead of HOST
- Minimize the number of SSH connections
- Use default STAGING_DIR
- Add possibility to choose the RBD_FORMAT
- Add possibility to add "-O rbd" to the "rbd" command line args
Reapply fixes for Bug #2110 and Bug #2271
Feature #2568: RBD format 1 as default. Handle properly both formats
Feature #2556: Create image without filesystem on ceph datastore
Feature #2556: Refactor Vladislav Gorbunov's contribution
Feature #2568: Fetch RBD format attribute from the VM in the TM scripts
Merge branch 'feature-2568'