Adding feature to configure upload size with annotation

Because there are some times we want to configure upload size with different values for another method. Or we want to configure a value without overriding a class.

If you like it, I'll add documentation.
Now I understood your point. But we already break compatibility in this version. And since this is a 4.1 there is no problem.

Because we already have another methods like this, I think that this is the best place. Creating this method under event class isn't good, because `getAnnotation` is related to controller method, and not about the event. And as I said the the previous, this is a 4.1 release, so its expected some changes in public interface.