[wsrp-wsia] change request, combine performInteraction and getMarkup

[Alejandro Abdelnur <alejandro.abdelnur@sun.com>]

Section: 6.2
Page: 40
Request by: Alejandro Abdelnur

Current:
getMarkup and performInteraction are 2 distinct operations.

Proposed:
Combine them in a single operation, drop current getMarkup and rename 
current performInteraction to getMarkup.

Reasoning:
The non-blocking interaction was added for the purposes of aligning WSRP 
and JSR168. However, it does not address the problem. JSR168 does not 
have the concept of non-blocking interaction. JSR168 allows properties 
to be modified during a getMarkup call, regarless of the user request 
being targeted to the portlet of being just a refresh (the user request 
targeted to another portlet).