Apply CfL even when bx=0 or by=0

subset1 results:
luma:
           RATE (%) DSNR (dB)
    PSNR -0.00866973 0.00043853
 PSNRHVS -0.00523201 0.000370351
    SSIM -0.00830849 0.000327202
FASTSSIM -0.00439319 0.000142907

Cb:
           RATE (%) DSNR (dB)
    PSNR -0.0790465 0.0032213
 PSNRHVS -0.139634 0.00692313
    SSIM -0.0925816 0.00250521
FASTSSIM -0.118561 0.00254396

Cr:
           RATE (%) DSNR (dB)
    PSNR -0.0507446 0.0028209
 PSNRHVS -0.0755671 0.0043902
    SSIM -0.0810965 0.00241197
FASTSSIM -0.536316 0.0119179
Remove frequency-domain intra prediction

We have been disabling it for a while and it is now broken (segfaults) due
to the 32x32 patch.
Merge branch 'remove_intra2'

Conflicts:
	src/intra.c
Splitting the joing gain/theta cdf into luma and chromas
Simplifying IIR averaging as requested in review 511

Rounding is slightly different so the bit-stream isn't fully compatible.
That being said, I got no desync over an entire image.
Adding some RDO cost to using the H/V predictor

subset1:
           RATE (%) DSNR (dB)
    PSNR -0.295475 0.0168111
 PSNRHVS -0.312016 0.0215276
    SSIM -0.2597 0.0118447
FASTSSIM -0.179223 0.00568647