Added a WeatherOverlay

OpenRA.Game/Graphics/WorldRenderer.cs

@@ -145,7 +145,6 @@ namespace OpenRA.Graphics
 			for (var i = 0; i < renderables.Count; i++)
 				renderables[i].Render(this);
 
-			// added for contrails
 			foreach (var a in World.ActorsWithTrait<IPostRender>())
 				if (a.Actor.IsInWorld && !a.Actor.Disposed)
 					a.Trait.RenderAfterWorld(this, a.Actor);

OpenRA.Game/Traits/TraitsInterfaces.cs

@@ -304,6 +304,7 @@ namespace OpenRA.Traits
 	}
 
 	public interface IPostRender { void RenderAfterWorld(WorldRenderer wr, Actor self); }
+
 	public interface IRenderShroud { void RenderShroud(WorldRenderer wr, Shroud shroud); }
 
 	public interface IPostRenderSelection { IEnumerable<IRenderable> RenderAfterWorld(WorldRenderer wr); }