o Minor bugfixes
    - Remove dead code from rend_cache_lookup_v2_desc_as_dir.  Fixes
      part of bug 2748; bugfix on 0.2.0.10-alpha.
    - Log malformed requests for rendezvous descriptors as protocol
      warnings, not warnings.  Also, use a more informative log
      message in case someone sees it at log level warning without
      prior info-level messages.  Fixes the other part of bug 2748;
      bugfix on 0.2.0.10-alpha.