transport_class_register — register an initial transport class
| int transport_class_register ( | struct transport_class * tclass ); | 
   The transport class contains an embedded class which is used to
   identify it.  The caller should initialise this structure with
   zeros and then generic class must have been initialised with the
   actual transport class unique name.  There's a macro
   DECLARE_TRANSPORT_CLASS to do this (declared classes still must
   be registered).
   
Returns 0 on success or error on failure.