Add the ability to test scaling when decompressing to YUV; compression from YUV to JPEG; and YUV padding.  Replace clunky -411 and -440 parameters with a -subsamp parameter that allows any of the subsampling options to be tested in isolation.
Add the ability to test scaling when decompressing to YUV; compression from YUV to JPEG; and YUV padding.  Replace clunky -411 and -440 parameters with a -subsamp parameter that allows any of the subsampling options to be tested in isolation.



bygreencn/mozjpeg,billychappell/mozjpeg,bygreencn/mozjpeg,m-2k/mozjpeg,ekandrot/mozjpeg,zhoujianhanyu/mozjpeg,zhoujianhanyu/mozjpeg,ekandrot/mozjpeg,zhoujianhanyu/mozjpeg,zhoujianhanyu/mozjpeg,billychappell/mozjpeg,zhoujianhanyu/mozjpeg,billychappell/mozjpeg,m-2k/mozjpeg,m-2k/mozjpeg,ekandrot/mozjpeg,ekandrot/mozjpeg,billychappell/mozjpeg,ekandrot/mozjpeg,bygreencn/mozjpeg,bygreencn/mozjpeg,m-2k/mozjpeg,billychappell/mozjpeg,bygreencn/mozjpeg,m-2k/mozjpeg