Currently we maintain two sets of getState and setState callbacks, one for byte based transfer and the other for stream based transfer. Users had to implement both types of callbacks if the wanted to interchange STREAMING_STATE_TRANSFER and STATE_TRANSFER. If we use only stream based callbacks we can simplify client code and users can choose what type of transfer they want as a protocol option of STREAMING_STATE_TRANSFER. Finally, we could potentially drop STATE_TRANSFER all together.