computedID in idpv3

[Rod Widdowson]

> I’m guessing the reason people think it’s deprecated is:
> 
> https://wiki.shibboleth.net/confluence/display/IDP30/ComputedIdConnector
> 

I'd forgotten about the transient nameid generator.   NB that SAML2-only deployments (== pretty much anybody but the UK ??) don't need it. 

But I'd better let Scott speak to that deprecation.

My bet is that because of the crazy SAML 1 thing will last longer than we really want to think about.
 
Rod