    encode_message
    encode_fastpack
        Encodes an array of fast pack message structures into an buffer

        Buffer is aliased and is an in/out parameter. Encoded data is
        appended to the buffer.

        Inputs is an array of message structure (also array refs). Array is
        consumed

        An optional limit can be sepecified on how many messages to encode
        in a single call

        Returns the number of bytes encoded

    decode_message
    decode_fastpack
        Consumes data from an input buffer and decodes it into 0 or more
        messages. Buffer is aliased and is an in/out parameter Decoded
        messages are added to the dereferenced output array An optional
        limit of message count can be specified.

        Returns the number of bytes consumed during decoding. I a message
        could not be decoded, 0 bytes are consumed.

          buffer (aliased) 
          output (array ref)
          limit (numeric)

          return (byte count)

