Remove Scale from IRenderable interface.

It is no longer used, and isn’t implemented for most renderables.

OpenRA.Game/Graphics/TargetLineRenderable.cs

@@ -28,12 +28,10 @@ namespace OpenRA.Graphics
 		}
 
 		public WPos Pos { get { return waypoints.First(); } }
-		public float Scale { get { return 1f; } }
 		public PaletteReference Palette { get { return null; } }
 		public int ZOffset { get { return 0; } }
 		public bool IsDecoration { get { return true; } }
 
-		public IRenderable WithScale(float newScale) { return new TargetLineRenderable(waypoints, color); }
 		public IRenderable WithPalette(PaletteReference newPalette) { return new TargetLineRenderable(waypoints, color); }
 		public IRenderable WithZOffset(int newOffset) { return new TargetLineRenderable(waypoints, color); }
 		public IRenderable OffsetBy(WVec vec) { return new TargetLineRenderable(waypoints.Select(w => w + vec), color); }