making events triggered on success consistent with those triggered on error

On error, best_in_place:error is triggered, however on success only ajax:success gets triggered, which makes it difficult to perform a specific action when a value is changed through best_in_place as opposed to just any ajax call.

This adds a trigger for best_in_place:success on success right alongside the triggered ajax:success event, which makes success/error both trigger a best_in_place event as well as an ajax event.