They do not handle border extension correctly (interpolation and
border extension do not commute unless you upsample into the
border), nor do they handle crop dimensions that are not a multiple
of 8 (the upsampled version is not sufficiently large), in addition
to using massive amounts of memory and being a criminal waste of
cache (1 byte used for every 8 bytes fetched).

This commit reimplements use_upsampled_references by computing the
subpixel samples on the fly. This implementation not only corrects
the border handling, but is also faster, while maintaining the
same quality.

HL AWCY results are basically noise:
    PSNR | PSNR HVS |   SSIM | MS SSIM | CIEDE 2000
  0.0188 |   0.0187 | 0.0045 |  0.0063 |     0.0228

Change-Id: I7527db9f83b87a7bb8b35342f7e6457cd0bef9cd