Helper script for cross compiling some media tools for windows, like customizable ffmpeg.exe (with or without non-free components, etc), and some other bonuses like mplayer, mp4box, mxf, etc.
This fixes compilation problems with libbluray (also mentioned in #497), libopus checkout and new problem with declaration clash of "dec_init", used in libbluray and ffmpeg (credit of BtbN).
This fixes compilation problems with libbluray (also mentioned in #497), libopus checkout and new problem with declaration clash of "dec_init", used in libbluray and ffmpeg (credit of BtbN).