Domain logic and convenience features for manipulating OMG Models

This module supplies domain logic add-on features for the common structural core of CWM, UML, and other OMG metamodels. Specifically, it adds some computed features, such as the notion of a "qualified name" of a model element, and the "superclasses" and "subclasses" of generalizable elements. It also gives namespaces a __getitem__ method for easy retrieval of object contents, and a find operation for running queries over a model.

This is basically a pure "advice" module; it should be placed in the patch list of an appropriately declared module.