Create camera controller to allow manipulation of camera at runtime to help find out what the best camera position is.

Using state_machine to manage input states.
Got horrible amounts of shaking for some reason.  Was not shaking
this much when testing state_machine-based method
earlier though.
Use nested private class instead of metaprogramming mess.
Clean up old structs and note values of first camera experiment.
Fix camera shake by not calling Oni::Camera#lookAt every frame.
Only convert position of entity followed by camera to array as necessary.