MOF14 — Provide tools to chapter 5 UML 1.3R9 draft

Summary: I would like to suggest that the UML model interface defined by Chapter 5 of the
UML1.3R9 draft provide tools the ability to register for notification of changes to the
model contents in a manner consistent with the Observer pattern.

This would provide a better mechanism for tool integration around a common
model respository, allowing each tool in a tool suite containing tools developed
by different vendors to present its own up to date "view" of the underlying model in
a simple fashion.