This to make sure that prediction residue always get coded in lossless
mode.
This commit also fixed lossless unit test
Change-Id: I537726ee55328d4e4cf0a0196393a67e12bfcde1
It does encodings with min and max q set at 0, and check to make sure
output PSNR at MAX_PSNR (100).
Change-Id: Ia2418353cccf6e487204ea4ff874a7e71e55cb3e