Desura compatibilty

You currently can't install/start OpenRA on the Desurium Linux client on. To fix this we are currently unpublished from http://www.desura.com/games/openra by DesuraNET staff. I already tweaked the install settings and prepared this patch for OpenRA. I do the MCF generation from a fresh install of an RPM from `/usr/share/openra` for Linux and NSIS Setup.exe from `Program Files/OpenRA` for Windows. Left some documentation on https://github.com/lodle/Desurium/wiki/Notes-For-Publishing-On-Desura because it is quirky.