Implemented the buffering of responses from the server. The previous imp...

...lementation kept crashing when the server sent back multiple chunks of data (TCP PUSH) because the protobuf construction happened regardless of we had the complete bytestream available or not. Now the buffering is backed by a BytesBuilder object and the protobuf construction will only take place if all data arrived. FIXME: Do something about timeouts and ensure that the buffer resets correctly.