yasm.exe that is needed to compile x264 and ffmpeg in windows (perhaps linux). copy to mingw/bin

在VS2005环境下编译成功的X264编码器，附有文档，希望可以帮到做流媒体开发的人-Compiled in VS2005 environment, the successful X264 encoder, with the document, the desire to help people make the development of streaming media