Possible toDo

1. Extend the GenericList to include all list methods

2. List of Lists?
Could we have a list where a Node has an element that is an Object and can be
of class (say) String or GenericList. We can then have a list of lists.

Key code snippet would be 

   (node.getElement() != null && node.getElement() instanceOf GList)

3. toString
... for lists of lists would be nice :)