An event is added to Map to indicate when the cell projection is changed. This is important as this can mean Map.Contains(CPos) could now return different results for the cell. The HierarchicalPathFinder is made aware of these changes so it can rebuild any out-of-date information. This fixes prevent a crash if a cell that was previously outside the map changes height and becomes inside the map. The local path search will explore the cell as it is inside the map - but if the HPF was unaware if had been updated, it will still consider the cell to be outside the map and unreachable, resulting in a crash.