Improve Logger for Operation Child Classes

The Operation class declares its logger this way:

public abstract class Operation {
  public static final Logger LOG = LoggerFactory.getLogger(Operation.class.getName());
  ...
}

Notice that this is an abstract class, but the Logger is tied to the Operation.class.getName(). This means that logging cannot be controlled for each subclass of Operation independently since they all use the same static Logger instance.

Make the LOG a protected instance variable that inherits the name of the child class.