Improves coding efficiency by about 1%, increases speed by
about 15-20% over exsiting speed 7.

Change-Id: Ibf5b9b5a5c8548e863ce19047c42b579aac21d19

Instead of using source variance, this patch uses variance of the
frame difference between the source and the current frame to make
fixed size partition decisions. Also disables adjusting partitioning
if variance based or fixed size partitioning is used.

The latter change improves the speed substantially for speed 6, so
that speed 7 is now less than 3x the speed of speed 6. But speed
6 is 48% better in psnr on the rtc set compared to speed 7.

As compared to speed 5,
speed 6 is -37% in psnr at about 2.5x the speed,
speed 7 is -55% in psnr at about 7x the speed.

Change-Id: If61d80431d3e04ed304ac05832e773cdb2c0a578

mismatch was introduced here:
abe21e42 Removing redundant vp9_clear_system_state() call.

Change-Id: I66f945c1ce385dddfdefa9f517f295dbdd01d286

* changes:
  variance_test: add NEON functions
  subtract_test: add NEON functions
  sixtap_predict_test: add NEON functions
  partial_idct_test: add NEON functions
  fdct8x8_test: add NEON functions
  fdct4x4_test: add NEON functions
  dct32x32_test: add NEON functions
  dct16x16_test: add NEON functions

note not all functions have NEON implementations:
- variance4x4_neon

Change-Id: I03c1ba21f3b02aa2482d7ca8feedc3ef74b5947f

Change-Id: I6d8ac50ce842749a2a643d8173bbd301cc284236

Change-Id: Id0a2d9ef9636c84ee988dabecd5d4dc2b8641944

note not all functions have NEON implementations:
- vp9_idct32x32_34_add

Change-Id: I3db3acbd5b33839aabd1beadc6e0742ec50b1072

FwdTrans8x8HT is disabled as the tests currently fail.

note not all functions have NEON implementations:
- fdct8x8/fht8x8

Change-Id: I028bdec9a21eaaee2c5865470ab179aac403540e

Trans4x4HT is disabled as the tests currently fail.

note not all functions have NEON implementations:
- fdct4x4/fht4x4

Change-Id: I26f8724bf2a9ea01d59205a1c57119ed25d043bc

note not all functions have NEON implementations:
- vp9_fdct32x32/vp9_fdct32x32_rd

Change-Id: I3795d78bf215e41ab8801c2c37cf633f16931f9d

Change-Id: I7b9738a7113c0c4687e5d320581ff69d98a8b271

Change-Id: I527c42fa776c772c26c027a47f3dada129f5c33e

There was a bug in the previous code that if GOLDEN was better than
LAST neither would be used. LAST would get turned off due to superior
GOLDEN quality then all GOLDEN modes would get skipped.

Change-Id: I173f3720451707dab7b2cbbe8b8e6a047089bde7

Removing all copies of identical vp8_mse2psnr/vp9_mse2psnr functions.
Using vpx_sse_to_psnr() instead in all places.

Change-Id: I15beef9834d43d8fc8a8a7a2d1fc5de3d658fed8

Change-Id: I197670a405f7c2e7796424faa187a61081db8567

Change-Id: I02f097fd7c4c787035f03114ddde5b04b2640b39

Change-Id: I747d26c544cc56feaaf7c75403f2f4c16a496bb7

Change-Id: I0b4fa1f8104b7fa5780d4e99e5401c14271a992d

Usage of encode_b_args is unnecessary because encode_block_pass1() doesn't
use them. That's why optimize_init_b() call is also not required.

Change-Id: Ib6cfe4916c2ca85749c90bb0adcba6fea592f9ac

Change-Id: Ia7677fb436667bc4f76db71f65e4784f433f7826