update avisynth.h

require Avisynth2.6.0 / Avisynth+MT r2005 or later.

improve more MT friendly

Set filter mode as MT_NICE_FILTER on Avisynth+ MT.
Use buffer pool on Avisynth+ MT.
Disable AVX2/FMA3/AVX code when /arch:AVX2 is not set.
Disable AVX2/FMA3/AVX code on Avisynth2.6.

Add AVX2 support for 32bit

1.1.1

Add AVX2 support for 32bit.

more optimized.

• Implement simd non-maximum-suppression.
• a bit optimized gaussian-blur/ hysteresis.
• Add EMask().

almost rewrite

• VS2013 to VS2015.
• Add AVX2(64bit only) / SSE4.1(both 32bit and 64bit) support.
• Change direction values from 1,3,7,15 to 31,63,127,255.
• Reduce waste processes.

0.2.0

cosmetics