core/or: Allow IPv6 connections to be canonical

  o Minor bugfixes (IPv6, relay):

    - Consider IPv6 addresses when checking if a connection is canonical.

      In 17604, relays assumed that a remote relay could consider an IPv6

      connection canonical, but did not set the canonical flag on their side

      of the connection. Fixes bug 33899; bugfix on 0.3.1.1-alpha.

  }

  if (r) {

    tor_addr_port_t node_ap;

    node_get_pref_orport(r, &node_ap);

    /* XXXX proposal 186 is making this more complex.  For now, a conn

       is canonical when it uses the _preferred_ address. */

    if (tor_addr_eq(&conn->base_.addr, &node_ap.addr))

    tor_addr_port_t node_ipv4_ap;

    tor_addr_port_t node_ipv6_ap;

    node_get_prim_orport(r, &node_ipv4_ap);

    node_get_pref_ipv6_orport(r, &node_ipv6_ap);

    if (tor_addr_eq(&conn->base_.addr, &node_ipv4_ap.addr) ||

        tor_addr_eq(&conn->base_.addr, &node_ipv6_ap.addr)) {

      connection_or_set_canonical(conn, 1);

    }

    if (!started_here) {

      /* Override the addr/port, so our log messages will make sense.

       * This is dangerous, since if we ever try looking up a conn by