Draft: Use libjpeg-turbo for JPEG decoding
TODO: Fall back to #undef WITH_SIMD
build if nasm/yasm is not found.
JPEG decoding became much slower after a6ac035a because Wine no longer used the host libjpeg, which was usually provided by libjpeg-turbo. Use libjpeg-turbo in Wine instead of plain libjpeg.
This adds a dependency on nasm or yasm to compile the i386/x86_64 assembly code.