CBD-798: Create recovery tool

Build upon cbtransfer platform and tap protocol.
Acting as tap consumer to retrieve vbucket data from one cluster.
Acting as tap producer to stream data to another cluster.
Each missing vbucket will be recovered one after another. And it
will be activated after all data for the vbucket is recovered.

The tool itself can be stopped anytime during recovery and it will
pick up whatever leftover since last run.

Change-Id: I34090de83438664e7c1e3db5fc0b3d4812dedbab