ISPN-4559 Replace fails with cache loader

https://issues.jboss.org/browse/ISPN-4559
https://issues.jboss.org/browse/ISPN-4649
No, `instanceof` is fine, I didn't realize you were doing a different check for writes.

I wonder if it wouldn't be nicer, though, if we added two new methods to _VisitableCommand_: _needsCacheLoaderValue_ and _needsRemoteValue_ (to cover the very similar code in `BaseDistributionInterceptor`).