tor-parallel-relay-conn/changes/prop110

  o Major features:
    - Now that Tor 0.2.0.x is completely deprecated, we can enable the
      final part of "Proposal 110: Avoiding infinite length circuits"
      by refusing all circuit-extend requests that do not appear in a
      "relay_early" cell. This change helps Tor to resist a class of
      denial-of-service attacks by limiting the maximum circuit length.