Try to fix 4x4 luma coding.
Try to fix 4x4 luma coding.

Still doesn't work. I have no idea what the problem is. Probably somehow related to the coefficient coding, since the bitstream seems to work, the prediction is correct and the error is not very severe.

- Change scan order selection to be more verbose and based on the correct mode for 4x4. Didn't affect the problem with 4x4 luma in any way although it should have.
- Re-enable residual coding as everything seems to work now besides 4x4 luma.

ultravideo/kvazaar,lu-zero/kvazaar,ultravideo/kvazaar,lu-zero/kvazaar,lu-zero/kvazaar,ultravideo/kvazaar,ultravideo/kvazaar,ultravideo/kvazaar,lu-zero/kvazaar