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
This is needed as unpacking msgpack yields bytes, and we need the blockids to be 'str'