NEW ISSUE: Clarify default function selection and data binding behavior

Target: JMS Binding specification

Description:
There is no obvious way for a Java implementation to manufacture a 
JMSMessage for a return value for the default data binding.

Also, it is traditional to carry XML in a BytesMessage, rather than a 
TextMessage.

Should we allow the selection of the operation from a document-wrapped 
XML message?

Proposal:
Drop the notion of returning a JMSMessage as the result of an operation.

Allow the use of BytesMessage and TextMessage to carry XML payload.

For any interface with multiple operations, either the scaOperationName 
must exist, or the operation name is taken from the name of the root 
element of the XML payload.