To be able to label incoming tor connections as different from normal localhost connections in e.g. `getpeerinfo` and the peers list in the GUI it'd be useful to have them connect on an alternative local-only port. Or even better, a UNIX socket.

For manually set-up hidden services this would have to be configured manually and could add a `hsport` option or such. The external port would still appear as `XXXXXXXXX.onion:8333`, however internally it would redirect to a that port.

In the case of `torcontrol` this would be easy to set up automatically. It could add a new (localhost) binding port automatically and this code would have to be changed:
- https://github.com/bitcoin/bitcoin/blob/master/src/torcontrol.cpp#L441
- https://github.com/bitcoin/bitcoin/blob/master/src/torcontrol.cpp#L477

std::vector<uint8_t> computedClientHash = ComputeResponse(TOR_SAFE_CLIENTKEY, cookie, clientNonce, serverNonce);
            _conn.Command("AUTHENTICATE " + HexStr(computedClientHash), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
        } else {
            LogPrintf("tor: Invalid reply to AUTHCHALLENGE\n");
        }
    } else {
        LogPrintf("tor: SAFECOOKIE authentication challenge failed\n");
    }
}
void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorControlReply& reply)
{
    if (reply.code == 250) {
        std::set<std::string> methods;
        std::string cookiefile;
        /*
         * 250-AUTH METHODS=COOKIE,SAFECOOKIE COOKIEFILE="/home/x/.tor/control_auth_cookie"
         * 250-AUTH METHODS=NULL
         * 250-AUTH METHODS=HASHEDPASSWORD
         */
        for (const std::string &s : reply.lines) {
            std::pair<std::string,std::string> l = SplitTorReplyLine(s);
            if (l.first == "AUTH") {
                std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
                std::map<std::string,std::string>::iterator i;
                if ((i = m.find("METHODS")) != m.end())
                    boost::split(methods, i->second, boost::is_any_of(","));
                if ((i = m.find("COOKIEFILE")) != m.end())
                    cookiefile = i->second;
            } else if (l.first == "VERSION") {
                std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);