General uncontroversial cleanup:

- Made private methods static where possible (runtime can elide checking the object for null).
- Declared attribute classes as sealed (allows reflection on attributes to complete faster).
- Moved some static cctor's into field initializers (static cctor's are slower than static field initializers).
- Made classes static if they contained only static methods (can't create instances of useless objects).
- Use inferable Exts.Lazy and not new Lazy<T>().
- Added required STAThread attribute to CrashDialog.
- Removed unused parameters in private methods.
- Added Serializable attribute to exceptions.
- Added parameter name in calls to ArgumentNullException.
- Use of as operator instead of is + cast.
- Changed (x as Foo).Bar anti-pattern into ((Foo)x).Bar. Results in sensible cast exceptions on error rather than null dereferences.
- Removed unused method in NullShader.

OpenRA.Game/Graphics/ContrailRenderable.cs

@@ -96,7 +96,7 @@ namespace OpenRA.Graphics
 			return j < 0 ? j + trail.Length : j;
 		}
 
-		WPos Average(params WPos[] list)
+		static WPos Average(params WPos[] list)
 		{
 			return list.Average();
 		}

OpenRA.Game/Graphics/Minimap.cs

@@ -17,7 +17,7 @@ using OpenRA.Traits;
 
 namespace OpenRA.Graphics
 {
-	public class Minimap
+	public static class Minimap
 	{
 		public static Bitmap TerrainBitmap(TileSet tileset, Map map, bool actualSize = false)
 		{

OpenRA.Game/Graphics/SheetBuilder.cs

@@ -14,6 +14,7 @@ using OpenRA.FileFormats;
 
 namespace OpenRA.Graphics
 {
+	[Serializable]
 	public class SheetOverflowException : Exception
 	{
 		public SheetOverflowException(string message)

OpenRA.Game/Graphics/SpriteFont.cs

@@ -134,12 +134,7 @@ namespace OpenRA.Graphics
 			return g;
 		}
 
-		static SpriteFont()
-		{
-			library = new Library();  
-		}
-
-		static Library library;
+		static Library library = new Library();  
 		static SheetBuilder builder;
 	}
 

OpenRA.Game/Graphics/VoxelLoader.cs

@@ -42,7 +42,7 @@ namespace OpenRA.Graphics
 		int totalVertexCount;
 		int cachedVertexCount;
 
-		SheetBuilder CreateSheetBuilder()
+		static SheetBuilder CreateSheetBuilder()
 		{
 			var allocated = false;
 			Func<Sheet> allocate = () =>

OpenRA.Game/Graphics/WorldRenderer.cs

@@ -57,7 +57,7 @@ namespace OpenRA.Graphics
 			Theater = new Theater(world.TileSet);
 			terrainRenderer = new TerrainRenderer(world, this);
 
-			devTrait = new Lazy<DeveloperMode>(() => world.LocalPlayer != null ? world.LocalPlayer.PlayerActor.Trait<DeveloperMode>() : null);
+			devTrait = Exts.Lazy(() => world.LocalPlayer != null ? world.LocalPlayer.PlayerActor.Trait<DeveloperMode>() : null);
 		}
 
 		PaletteReference CreatePaletteReference(string name)