Fix Linux Build system for 0.4.3

So, I haven't got it completely *working* on linux quite yet. There's still some issue where at least one thread doesn't properly get the GL info when starting up, and that causes it to hit a std::logic error when it tries to initialize a string off of a NULL const char *. But the UI starts and compiles fine, and it doesn't crash until you attempt to launch a game. I think it may be more productive to push this (finished) part up now and start an issue to fix the Linux launch.