[wsrp-wsia] [change request #51] Extensions description

[Rich Thompson <richt2@us.ibm.com>]

Document: Spec
Section: 5.1.1
Page/Line: 19/20 
Requested by: Michael Freedman
Old text: after "as part of containing data structures"
Proposed text: [insert] "They are designed to communicate extended 
information between the Consumer and Producer.  They aren't designed to 
communicate extended information in a roundtrip between either the 
Consumer itself or the Producer itself.  I.e. neither the Consumer or the 
Producer should expect to receive the extensions back that it returned or 
passed in a structure in subsequent requests or responses."
Reasoning: We have a number of data structures that are repeatedly 
supplied to the Producer.  We should make it clear that the Producer can't 
use the extensions field of these structures to pass/maintain state. 
Likewise for the Consumer.