o Security fixes:
    - Don't attach new streams to old rendezvous circuits after SIGNAL
      NEWNYM.  Previously, we would keep using an existing rendezvous
      circuit if it remained open (i.e. if it were kept open by a
      long-lived stream or if a new stream were attached to it before
      Tor could notice that it was old and no longer in use and close
      it).  Bugfix on 0.1.1.15-rc; fixes bug 3375.