rigaya/NVEnc 3.31 on GitHub

Fix crash when using "%" character in output file. ( #36 )
Add "--avsync vfr" option for vfr output when using avhw/avsw reader. ( #37 )
Please note that this could not be used with --trim.
Fix --trim option having up to 2 frame delay on some input files.
Limit decoder threads to 16 in avsw reader. (fix warning from libavcodec)