issue 7728: point 1 - proposal for indicating effective endpoint policy in an EPR

I've attached the first draft of our proposal for incorporating WS-PAEPR 
into WS-Mex [1] to the entry for issue 7728. This is accomplished by 
creating a new section, Section 7.2, that describes what it means to put 
a wsp:Policy or wsp:PolicyReference in a 
wsa:EndpointReference/wsa:Metadata element.

Note this addresses the WS-DD comments ([2], [3]) made on 
WS-MetadataExchange by Antoine Mensch.

[1] http://www.w3.org/Bugs/Public/attachment.cgi?id=775
[2] 
http://lists.w3.org/Archives/Public/public-ws-resource-access/2009Oct/0027.html
[3] 
http://lists.w3.org/Archives/Public/public-ws-resource-access/2009Oct/0033.html\ 
<http://lists.w3.org/Archives/Public/public-ws-resource-access/2009Oct/0033.html>

- gp