A tight binary codec for packet-streams (the internal component to muxrpc)
This allows streams of binary data, and also supports json objects. (although, you can't send a buffer inside a json object, but so far we have not done this in secure-scuttlebutt, so performance is more important)
The protocol sends zero or more header:body pairs, then a final header that is all zeros.
( [flags (1byte), length (4 bytes, UInt32BE), req (4 bytes, Int32BE)] [body (length bytes)] ) * [zeros (9 bytes)]
flags indicates the encoding type of the body, and whether it's
part of a stream, or an error/end value.
flags is just one byte.
end/type = Buffer String JSON