Faster CABAC CBF context calculation for inter blocks.
Add x264_constant_p(), will probably be useful in the future as well.
Simpler subpartition functions.
Clean up and optimize mvd_cpn a bit more.
Various other minor optimizations.

Faster CABAC mvd coding.

Smaller code size, plus I get to use goto.

ssim_end4_sse2 requires aligned sums

The real reason I wrote this was an excuse to use shufpd.

configure check for -mno-cygwin, since it's removed from gcc4.

2-4% faster dia, hex, and umh.

this change is useless on its own, but segregates the bitstream-changing part out of my next optimization.

x264 will now correctly warn about maxrate specified without bufsize even when a level is not set.

Broke --me esa/tesa due to forgetting to add handling for x264_cost_mv_fpel.

Faster subme<=1 with i4x4 enabled.

Have quantizers that use the same lambda share the same cost array.

Backport CAVLC partial-inlining early termination to CABAC (~2-4% faster CABAC residual coding)

Disabling asm will default to a generic arch.
Also fix configure for gcc 4.4.

3% faster CAVLC RDO and bitstream writing.

unroll/tweak col_zero_flag

Simplified function calling for block_residual_write_(cabac|cavlc) and improved sigmap coding.
Tried making 0/1-bit specific versions of CABAC asm, but benefit was minimal under GCC 4.3.
Helped a decent bit under 3.4, but you shouldn't be using such old versions anyways.

Move some macros to x86util.asm that should have been there to begin with.
Fix a typo that didn't cause any issues.

fix "incompatible types in initialization" compilation issues with GCC 4.3 (which is stricter than previous compiler version)

This measures the total percentage of blocks, intra and inter, which have nonzero coefficients.
"y,uvAC,uvDC" refers to luma, chroma DC, and chroma AC blocks.
Note that skip blocks are included in this stat.

I'm not entirely sure how this snuck its way out of holger's intra pred patch.

shufps is the most underrated SSE instruction on x86.

Move calculation of b_intra out of the core residual loop and hardcode it where applicable.
Inlining cabac_mb_mvd was unnecessary and wasted tremendous amounts of code size.  Inlining only cache_mvd is faster and significantly smaller.

faster bs_write_te, port CABAC context selection optimization to CAVLC.

Since the bypass case is quite unlikely, especially when doing merged sigmap/level coding,
it's faster to use a branch than a cmov.

Also fix intra_sad_x3_16x16's use of "n" as a loop variable (broke SWAP)