Update to refactoring the ebMS schema

Here are updates to the refactored ebMS 3.0 Part 1 header
schema and to the Part 2 Intermediary schema.

1)  the ebMS 3.0 header schema:
-  The UserMessage type references MessageInfo, PartyInfo,
CollaborationInfo, MessageProperties and PayloadInfo
elements instead of having local elements.
-  A more complete set of SOAP 1.1 and SOAP 1.2 attributes
is included.  

An example is included.

2) the ebint schema: 
-  Now references the relevant elements from the refactored
core schema.

An example is included for this too.

Please review them for a future TC meeting ..

Once these are approved and stored at the docs.oasis-..
site, the schemaLocation values must be updated.

Pim