MFA result reuse with Duo.

[O'Dowd, Josh]

Thanks again for the ideas.

> I did ask several times on -dev for use cases to validate the design, but I didn't get any.

Yes, sorry, at the time, we were very early in talks with Duo and getting Demo set up.  At that time I didn't have the current requirements that I am trying to satisfy today.  We are still in the demo/decision stages with Duo but they are getting close to a commitment, so I am getting a clearer picture of our initial use case.

I will do what I can to get something going in the RelyingParty.xml, while I do recognize that I cannot filter on user attributes at that point.

Thanks.
-Josh