Hotfix: Linux and Fog — Cataclysm: The Last Generation Steam update #673742

I rolled out the Linux version last night, and was dismayed but not surprised to discover there were some issues with it. One of those was on me (you would not believe how byzantine the Steampipe stuff is for devs), while the other was apparently a longstanding issue with Cataclysm and Steam's Linux runtime. The former prevented the game from running at all, and once fixed it revealed the latter issue, apparently a UTF decoding problem that was causing a crash when you got behind the wheel of a car. If you don't know what that means, well, neither do I, but I think I fixed it. So hopefully that's that. Please let me know if it's not. There was also an issue across all OSes with the fog overlay being a little flickery and breaking some tilesets during foggy weather. While tracking this down, I made a number of improvements and optimizations. Fog shouldn't flicker anymore. If you find it s...