Disallow eppn/affiliation to be asserted by the wrong IdP

[Peter Schober]

* William Spooner <william.spooner at eaglegenomics.com> [2012-10-11 13:33]:
> I think the penny has dropped! I just need to edit my
> MetadataProvider XML with the 'correct' IdP scope, and then read
> e.g. "emailaddress" with a ScopedAttributeDecoder in
> attribute-map.xml. Cool!

Check out the distributed default attribute-policy.xml -- it's all
done in there.
-peter