T2 Type Attribute for Sender/Receiver

The Sender and Receiver elements (8.5.2.1 & 8.5.2.2) each need a "Type"
attribute to match the To and From elements.  This is necessary since there may
be multiple PartyId elements in a single TraceHeader.  As with To and From, the
"Type" should default to URI.

Add another paragraph to 8.5.2.1.1:

The PartyId MAY have a single type attribute (see section 8.4.4.1).


Regards,

David Fischer
Drummond Group.

Ian, do you still want each issue in a separate eMail?