Since Tor 0.2.9 has been unsupported since January, 0.3.5 is the
oldest supported version, and its features constitute the oldest
recommended feature-set.

This patch updates these recommendations:

   DirCache=2

      Support for consensus diffs.
      New in 0.3.1.1-alpha.

   HSDir=2

      Support for v3 onion service descriptors.
      New in 0.3.0.4-alpha.

   HSIntro=4

      Support for Ed25519 intropoint authentication keys.
      New in 0.3.0-4-alpha.

   HSRend=2

      Support for rendezvous cells longer than 20 bytes.
      New in 0.2.9.4-alpha.

   Link=5

      Link padding and link padding negotiation.
      New in 0.3.3.2-alpha.

   LinkAuth=3

       Ed25519 link authentication.
       New in 0.3.0.1-alpha.