Clean up styles

I've begun the work of making the implementation of style methods more uniform and correct, but this got to be so big that I decided to stop half-way.

This PR will represent "cleaning up" `arc` - `list_box` (using the list in #711).

I'll make lots of inline comments on what I considered "cleaning" and I'm eager to hear feedback.
Nah I see your point here. You simply want to retrieve a value which you know is there. 

However, it won't check for `style_changed?` as when we call `style[:click]` there is no argument passed to the style method which is why `need_to_update_styles?` will immedeatly return false, so that in the end `@style` is returned almost directly.