Convert AnimationWithOffset to world coords.

Animations (via Actor.CenterPosition) now
understand Altitude, so there is potential for
mis-positioned animations if any existing altitude
hacks were missed.

OpenRA.Mods.RA/Render/WithRotor.cs

@@ -32,10 +32,9 @@ namespace OpenRA.Mods.RA.Render
 
 			rotorAnim = new Animation(rs.GetImage(self));
 			rotorAnim.PlayRepeating("rotor");
-			rs.anims.Add(info.Id, new AnimationWithOffset(
-				rotorAnim,
-				wr => wr.ScreenPxOffset(rs.LocalToWorld(info.Offset.Rotate(rs.QuantizeOrientation(self, self.Orientation)))),
-				null ) { ZOffset = 1 } );
+			rs.anims.Add(info.Id, new AnimationWithOffset(rotorAnim,
+				() => rs.LocalToWorld(info.Offset.Rotate(rs.QuantizeOrientation(self, self.Orientation))),
+				null, 1));
 		}
 
 		public void Tick(Actor self)