Not started servers need a placeholder resource when added

In ServerAddHandler where the server resource is created, a placeholder should be added. I.e. instead of context.createResource(...) below

context.addStep(runningServerAdd, new OperationStepHandler() {
@Override
public void execute(final OperationContext context, final ModelNode operation) throws OperationFailedException

{ context.createResource(PathAddress.EMPTY_ADDRESS); context.stepCompleted(); }

}, OperationContext.Stage.MODEL, true);

context.addResource(PathAddress.EMPTY_ADDRESS, PlaceholderResource.INSTANCE) should be used instead. Otherwise, servers that are not started at boot will be missing runtime proxies and will be considered as parts of the persistent model.