Changed the harvester heuristic so that now takes into account the distance from the initial search location. This makes harvesters somewhat more "intelligent" and gather nearer resources. Also solved several regressions introduced in the recent changes in the Pathfinder

OpenRA.Mods.Common/Pathfinder/PathCacheStorage.cs

@@ -60,7 +60,6 @@ namespace OpenRA.Mods.Common.Pathfinder
 					return null;
 				}
 
-				cached.Tick = world.WorldTick;
 				return cached.Result;
 			}
 

OpenRA.Mods.Common/Pathfinder/PathSearch.cs

@@ -88,6 +88,13 @@ namespace OpenRA.Mods.Common.Pathfinder
 			var currentCell = Graph[currentMinNode];
 			Graph[currentMinNode] = new CellInfo(currentCell.CostSoFar, currentCell.EstimatedTotal, currentCell.PreviousPos, CellStatus.Closed);
 
+			if (Graph.CustomCost != null)
+			{
+				var c = Graph.CustomCost(currentMinNode);
+				if (c == int.MaxValue)
+					return currentMinNode;
+			}
+
 			foreach (var connection in Graph.GetConnections(currentMinNode))
 			{
 				// Calculate the cost up to that point