[ebxml-cppa-negot] Message Content Update based on last conf call

[Jean Zheng <Jzheng@vitria.com>]

I've made some update to Message Content based on our discussion during
last conference call.
Main Changes are:
1. add in a Security section for "InitiatingCPANegotiation" message.
2. Add in enumerated list for CPA status and reason for rejection.
3. Move Tentative Process section to the end.

Any help in adding more details to any of these sections are very
welcome!  Especially in the Security section.

Thank you!
Jean

NegotiationMessageContent.doc