cannot tell which combo triggered the callback

[ittayd]

In mousetrap, the second argument of the callback is the key that cased it to trigger which is good if registering a few keys to the same callback. But angular-hotkeys calls the callback with the hotkey definition. While this is useful for using the same callback across registrations, I think it is important to retain the ability to register multiple hotkeys with the same callback and make the distinction ini it