add RALint checking to nearly everything

OpenRA.Mods.RA/Bridge.cs

@@ -21,9 +21,7 @@
 using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
-using System;
 using OpenRA.FileFormats;
-using OpenRA.GameRules;
 using OpenRA.Graphics;
 using OpenRA.Traits;