Impl5 of WL2278 - dynamic port allocation for cluster nodes

Treat the management server specially.

It should always be the server in a transporter as we then have a known
port to connect to on node restart.

allows a mgm connection (i.e. to the management server port, our known port)
to be transformed into a transporter connection.

Also, clean up the struct TransporterConfiguration (used to be a struct for
each transporter type. now there's just one)

ndb/include/util/SocketClient.hpp

@@ -36,6 +36,7 @@ public:
     m_servaddr.sin_port = htons(m_port);
   };
   NDB_SOCKET_TYPE connect();
+  NDB_SOCKET_TYPE connect_without_auth();
   bool close();
 };