[wsrm] [REL-51] Proposal for discussion

REL-51 Acknowledgement piggybacking
  
Hitachi would like to see 
support for acknowledgement piggybacking to
    a. optimize 
performance and reduce 
traffic
    b. provide an alternate to 
REQ/RESP-MEP

   REL-51 Proposal.
   
Enable acknowledgement piggybacking by removing the distinction
   
between Reliable Message and Acknowledgement Message.
   
Specifically, 
     1) Remove the MessageType 
element.
     2) Any RMResponse element could coexist with other 
elements.