Refactor NoteBox to use Blitting instead of a DisplayList.

[Zageron]

Is your feature based on a frustration?
rCubed is a high precision engine with a large number of moving objects on screen. The display list doesn't lend itself to displaying tens of very rapidly moving objects. The issue is exacerbated with the addition of text on screen, some of which overlaps the arrows as they move up screen.

If so, Describe the solution you'd like
Instead of using Sprites and MovieClips, noteskins will be rendered into a cached bitmap and then painted onto a single bitmap image once per frame. That single bitmap will then be painted to the screen. This, at the very least, will allow the majority of the source of the lag to be mitigated. Receptors, accuracy, and borders may follow.

And, Describe alternatives you've considered
Literally nothing. Too laggy.

[Zageron]

Done!