Binary Encode/Decode

[benjchristensen]

Replace the ASCII placeholder with binary as being defined in the protocol: https://github.com/ReactiveSocket/reactivesocket/blob/master/Protocol.md

[benjchristensen]

Note that thus far I've used the term "Message" for the object doing the encode/decode. All code as currently exists should change to match the evolving protocol, including the terminology: https://github.com/ReactiveSocket/reactivesocket/blob/master/Protocol.md#terminology

Thus, it probably should get renamed to Frame.

[benjchristensen]

Working.