Use GitHub Releases

as discussed in OpenRA/OpenRA#3764 an alternative to https://github.com/OpenRA/OpenRAWeb/pull/93. During the live stream that made us popular over night, people had very slow downloads, see http://www.reddit.com/r/Cynicalbrit/comments/1wwhnb/command_conquer_red_alert_because_why_not/cf67jda for example.