IdP 3.4: Deprecated items in custom Syntax

[Rod Widdowson]

> If it's separate from the 4.0 upgrade material, I guess probably in a top level page under Configuration down near the bottom of
that list.

To my mind it is right now.  It’s a "list of elements and namespaces that will generate deprecation warnings in 3.4".  That will
(obviously) transmogrify into a "No longer supported in V4" list when we start down that track...

R