Convert non-aircraft positioning to world coords.

This removes the incomplete and unused hover code
on Mobile, which would be more trouble that it is
currently worth to carry over.

OpenRA.Game/Traits/Waypoint.cs

@@ -13,7 +13,7 @@ using OpenRA.FileFormats;
 
 namespace OpenRA.Traits
 {
-	class WaypointInfo : ITraitInfo
+	class WaypointInfo : ITraitInfo, IOccupySpaceInfo
 	{
 		public object Create( ActorInitializer init ) { return new Waypoint( init ); }
 	}
@@ -28,10 +28,7 @@ namespace OpenRA.Traits
 		}
 
 		public CPos TopLeft { get { return location; } }
-
 		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { yield break; }
 		public WPos CenterPosition { get { return location.CenterPosition; } }
-		public PPos PxPosition { get { return Util.CenterOfCell(location); } }
-		public int Altitude { get { return 0; } set { } }
 	}
 }