Speed up the scroll when bot runs on ledbone

- Tried cleaning out for-loops in our code, for getting pixel data.  It didn't help because the opc client itself looped over the pixels and did a bunch of sanity checks on it.
- Fixed it by sending it raw data directly, using the raw data from PIL's `image.tobytes`
- Due to some wonkiness, RGB data returned by PIL is interpreted as BGR data.  So, we just reverse the string we send, which flips the display, but everything works.