ISSUE: [Primer] Issue 4857 - Updates for Nested Policy Expression and Context

Target:
http://dev.w3.org/cvsweb/%7Echeckout%7E/2006/ws/policy/ws-policy-primer.html?content-type=text/html;%20charset=utf-8
Target document: Primer

Description: Updates to Primer are proposed for context and nested policy expressions that are consistent with the Guideline changes discussed, proposed
or agreed. See section 2.9:
http://dev.w3.org/cvsweb/%7Echeckout%7E/2006/ws/policy/ws-policy-primer.html?content-type=text/html;%20charset=utf-8#nested-policy-expressions

Updates proposed are found in .doc and .pdf attached. Thanks.

MaryAnn Hondo 
Fabian Ritzmann
Tom Rutt
Monica J. Martin