[XACML-Usecases] ebXML Registry Use cases

Here is the ebXML Registry access control use cases doc.
I have put together. I am not planning to have any slides,
and will bring copies to the f2f.

The attached paper explains the domain somewhat.
In all fairness, the ebXML Registry spec related to this area
is still shaky and is being worked on, so expect to
see inconsistencies and open flanks. XACML point of view will 
be useful as feedback.

Cheers,
-Suresh