message: Add missing forward declares for Robot and Tile
diff: @@ -19,10 +19,12 @@ namespace NAS2D {
  }
  }
  +class Tile;
  class TileMap;
  class Warehouse; /**< Forward declaration for getAvailableWarehouse() function. */
  class RobotCommand; /**< Forward declaration for getAvailableRobotCommand() function. */
  class RobotPool;
  +class Robot;
  struct StorableResources;
  using RobotTileTable = std::map<Robot*, Tile*>;
  