Update to "A Brief Introduction to XACML"

After we contributed our XACML implementation to SourceForge, we
made some updates to the documentation.  Attached is the
corresponding update to "A Brief Introduction to XACML".  This
updated contribution should replace any copies people have of the
original contribution, as it corrects some errors in the
original.

Anne
-- 
Anne H. Anderson             Email: 
Sun Microsystems Laboratories
1 Network Drive,UBUR02-311     Tel: 781/442-0928
Burlington, MA 01803-0902 USA  Fax: 781/442-1692