* Streaming:

      - Make flush() block less, by waiting only for "accept" into the
        streaming queue rather than "completion" (i.e. ACK from the far end).
        This prevents complete window stalls when flushing, and should help performance
        of apps that use flush(), like i2psnark (and SAM?).
        close() still does a flush that waits for completion, as i2ptunnel
        doesn't like a fast return from close().
      - flush/close javadocs and comments
    * i2ptunnel:
      - Now that streaming flush() is fixed, use it in IRCClient, and
        for initial data in I2PTunnelRunner, to avoid the 250 ms
        passive flush delay