This patch activates all the preceeding work, moving Daala TX to a
greater, fixed coefficient depth (12).  This reclaims the regression
caused by going to Q3.

subset-1:
monty-rest-of-stack-rmscale-s1@2017-11-13T14:40:20.646Z ->
 monty-rest-of-stack-Q4-s1@2017-11-13T14:40:44.807Z

   PSNR | PSNR Cb | PSNR Cr | PSNR HVS |    SSIM | MS SSIM | CIEDE 2000
-0.0745 |     N/A | -0.1040 |  -0.1017 | -0.0660 | -0.0522 |    -0.0806

Change-Id: If2a0853b320d57c2fa3a66f919ceb2dc526d017f