tor/changes/prop176

  o Major features
    - Implement a new handshake protocol for authenticating Tors to
      each other over TLS. It should be more resistant to fingerprinting
      than previous protocols, and should require less TLS hacking for
      future Tor implementations.  Implements Proposal 185.
    - Allow variable-length padding cells to disguise the length of
      Tor's TLS records.  Implements part of Proposal 184.