VE-743 VisualEditor orientation dialog

Yeah, that's what FIXME I added is about. Theoretically you might be using just one config property and then assigning it to variable and using only once would be actually a cost without benefit. On the other hand, for width and height I would expect both of them to be set or neither.
Given the circumstances - @mklucsarits is the original author, it would be microoptimization, we want to finish it today - I decided to just mark it as FIXME, so he can handle it later.