Multiplexer / Streamer race condition, Infinite loop

[datasedai]

As follows:

1. A multiplexed stream is established
2. Host A writes to stream and calls end()
3. Host A ends stream on next tick, streamer deletes reference to stream
4. Host B reads and writes response back to host A
5. Host B reads 'end', calls end() and removes reference to stream in mux-stream and streamer
6. Host A reads stream data from Host B. Streamer does not know about stream, creates a reference and passes the message to mux-stream. Mux-stream does not know stream id, replies with p:error
7. Host B reads p:error and doesn't know stream, replies with p:error ... and on and on

Two problems occur:

1. The infinite p:error loop
2. The leaking of references to non-existent streams in streamer. Streamer trusts that any message for any stream it doesn't know about is a 'new' message, and passes it onto the multiplexer with that assumption.