This class searches the type heirarchy looking for abstract methods that
have not yet been instantiated. Abstract methods are gathered into a
linked list.
This object is used by CreateClass to build a list of abstract methods
that the user will have to overload.
author: Chris Seguin
Removes those methods which have been instantiated (and adds abstract
methods). Uses recursive processing to traverse through the parent
classes first.
Parameters: current - The current type summary