GtkCList::set_reorderable
void set_reorderable(bool reorderable); 
    
     Sets whether the CList's rows are re-orderable using drag-and-drop. If it is set to true, 
     the user can select one with the mouse, hold the left mouse button and move it to another
     position in the list. The row-move 
     signal is emmited when the user did so.