feat(multiple block post): Swift and Disk

Deuce:
    POST v1/{vaultname}/blocks
        -Request body : msgpacked content of
                        dictionary of blockid
                        and blockdata
Swift:
    Asynchronous multiple block post
    py27 - gevent
    py33,34 - aiohttp and asyncio
            - lacks exception handling
Disk:
    Reference Driver
    Synchronous multiple block post
If I post blocks without body:
response = self.app.post(self._blocks_path, headers=self._hdrs)

block controller will raise an exception "UnpackValueError" @ blocks.py::post()
111         unpacked = msgpack.unpackb(request.body_file_seekable.getvalue())

Maybe a try is needed around msgpack calling.