Use histogram_bits to initalize transform_bits.

This change gains back 1% in compression density for method=3 and 0.5% for
method=4, at the expense of 10% slower compression speed.

Change-Id: I491aa1c726def934161d4a4377e009737fbeff82
Add SSE2 version of forward cross-color transform

Encoding speed is roughly the same.

Change-Id: I6b976d0eb24e1847714e719762cb8403768da66c
Merge "Add SSE2 version of forward cross-color transform"
add intrinsics NEON code for chroma strong-filtering

The nice trick is to pack 8 u + 8 v samples into a single uint8x16x_t
register, and re-use the previous (luma) functions

Change-Id: Idf50ed2d6b7137ea080d603062bc9e0c66d79f38
Merge "add intrinsics NEON code for chroma strong-filtering"
cosmetic: fix long line

Change-Id: Id04b368aea5784a98c705f323b32d35b362742ea
dec_neon: use vld?_lane instead of vset?_lane

results in fewer instructions, small speed improvement

Change-Id: I61ab48d09a5ce7c5158eac8244d28287457edc7a
dec_sse2: drop SSE2 suffix from local functions

Change-Id: Ie171778b84038d5b04c5dc6972f6015caf555882
enc_sse2: drop SSE2 suffix from local functions

Change-Id: I5d61605a9d410761d50b689b046114f0ab3ba24e
upsampling_sse2: drop SSE2 suffix from local functions

Change-Id: I2349c1a8e5e15e1d204642096f84f3202721c297
upsampling_neon: drop NEON suffix from local functions

Change-Id: I6583ad74aacf78dcbeb5a0ff0218a39bc3460e5a
Merge "dec_neon: use vld?_lane instead of vset?_lane"
Intrinsics NEON version of TransformOne

+ misc cosmetics

* seems 4% slower than inlined-asm with gcc-4.6
* is a tad faster (<1%) with gcc-4.8
(disabled for now)

Change-Id: Iea6cd00053a2e9c1b1ccfdad1378be26584f1095
dec_neon: use vst_lane instead of vget_lane

results in fewer instructions, small speed improvement

Change-Id: I98de632d09ff09f295368c0d744cb4397b585084