* Improved the bandwidth throtting on tunnel participation, especially for
      low bandwidth peers.
    * Improved failure handling in SSU with proactive reestablishment of
      failing idle peers, and rather than shitlisting a peer who failed too
      much, drop the SSU session and allow a new attempt (which, if it fails,
      will cause a shitlisting)
    * Clarify the cause of the shitlist on the profiles page, and include
      bandwidth limiter info at the bottom of the peers page.