Aspect Ratio Support [3:2, 4:3, 5:4, 15:9, 16:10, 21:9, and 32:9] (Updated for 1.09)
Choose the xgcore.dll for the folder for whatever aspect ratio you want. If you run into an error, I believe you have to start the game from the executable instead of Steam. I don't know about EAC, because I never play online (too antisocial).
Added a backup copy of the original in case you wanted to switch back.