* Fix during the ssu handshake to avoid an unnecessary failure on
      packet retransmission (thanks ripple!)
    * Fix during the SSU handshake to use the negotiated session key asap,
      rather than using the intro key for more than we should (thanks ripple!)
    * Fixes to the message reply registry (thanks Complication!)
    * More comprehensive syndie banning (for repeated pushes)
    * Publish the router's ballpark bandwidth limit (w/in a power of 2), for
      testing purposes
    * Put a floor back on the capacity threshold, so too many failing peers
      won't cause us to pick very bad peers (unless we have very few good
      ones)
    * Bugfix to cut down on peers using introducers unneessarily (thanks
      Complication!)
    * Reduced the default streaming lib message size to fit into a single
      tunnel message, rather than require 5 tunnel messages to be transferred
      without loss before recomposition.  This reduces throughput, but should
      increase reliability, at least for the time being.
    * Misc small bugfixes in the router (thanks all!)
    * More tweaking for Syndie's CSS (thanks Doubtful Salmon!)