Integrate Arakoon on RocksDB

[wimpers]

@delamonpansie is finishing up the move from Tokyo cabinet to RocksDB for Arakoon openvstorage/arakoon#128. This will have an impact on framework scripts and processes. A few areas where thing might be impacted.

• policies on collapsing need to be adjusted (RocksDB doesn't need it), You still want to call collapse for removing old tlogs.
• Copy of the DB procedure (copy DB to head, inject head can no longer be done). You should use snapshots.
• Setup scripts