SAML artifact config support

[Rod Widdowson]

> One question I had, Rod, did you ever manage to get a property replacement
> to work with a custom config schema?
> 

Yes, I cannot remember the details but I will dig out the mail tomorrow.  If you look in the tests for idp-core there is a package called 'nature study' which has the examples of this working, as I recall there was some slight manipulation needed..

Rod