Change animations to use the proper SequenceProvider

Remove references to the global "Game" and use the SequenceProvider
of the current world/map.

OpenRA.Mods.RA/Effects/Corpse.cs

@@ -28,7 +28,7 @@ namespace OpenRA.Mods.RA.Effects
 			this.pos = pos;
 			this.cell = pos.ToCPos();
 			this.paletteName = paletteName;
-			anim = new Animation(image);
+			anim = new Animation(world, image);
 			anim.PlayThen(sequence, () => world.AddFrameEndTask(w => w.Remove(this)));
 		}