XStream modules are using to be deleted Java APIs - Java9 version

[gorky]

XStream modules are using

• inefficient Java APIs that are being deprecated and access will be restricted to
• APIs that have been deprecated in Java 9 (or earlier) and will be deleted.

While not yet urgent, invocations of these APIs should be updated.

[gorky]

I have a tool that is handling a bunch of this. Updates should be along shortly.