[ogsa-wg] Updated Express AuthN Profile docs

All, I've updated the three EAP security profile documents on Gridforge with some minor revisions, including clarifications, fixes to requirement-numbering inconsistencies, and added an example SOAP message meeting the requirements of the X.509 message-level binding assertion policy. A question for the group: Would it be a good idea to also profile a Kerberos message-level binding assertion policy within the OGSA-SP-SecureSoapMessaging profile? The document currently profiles X.509 and UsernameToken binding policies, primarily because of their widespread use / ease-of-adoption. Thoughts? Duane