[x] crop_x and crop_y, as a way to allow sprites to disappear under the left and top edges.
. Adds to scroll_x and scrool_y, but max out at 256 - width and LINE_COUNT - height
[x] Scanline cache in iterator
[x] FG Flag for BG tiles
[x] Flip and rotate flags for BG Tiles
[3] 3 bit per channel RGB
[ ] Test with a real project!