Deprecate all java.util.concurrent.*FieldUpdater

[Remi Forax]

Given that Java 9 introduces a faster way to emit things like compareAndSet by using the VarHandke API and that AtomiReference (and likes) are now rewritten to use VarHandles directly,
i think it's time to deprecate all *FieldUpdater with something saying that they have been superseded by the VarHandle API.

Rémi
substitute dr deprecator