[wsrp] [CR313] - Clarify cookie guidance

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

Document: Specification
Requested by: Subbu Allamaraju
Section: 6.4 initCookie() Operation
Page: 31
Old Text:
New Text: (addition at the end of line 15)
However, since such reprocessing usually incurs additional processing and
network overhead, Producers are encouraged to process the request as usual
and return new cookies along with the response. Consumers MUST process
and resupply such cookies as per Section 3.11.

Compatibility Issues: This change does not
affect the Producer behavior. Section 3.11 already requires Consumers to
process and return such cookies.

Reasoning: This change clarifies brings up
the issue of possible negative impacts of reprocessing, and provides guidance
on how best to handle invalid cookies.