Implements the volume driver that supports file backed cinder volumes.
Resolves long standing issue with how our volume adapters are created
and now allows for a single host to support multiple different volume
types at once.
This is considered experimental. Full support should land in Pike.
To use, the NovaLink nightly builds must be utilized.
Change-Id: Ia78d2ed17232cc0f42fed1391786384e4dea28c1
Partially-Implements: bp/file-io-cinder-connector
ebee3eae88