Chunnel: Use hash table for tunnel search, change tunnel fields and savegame format.

src/saveload/afterload.cpp

@@ -2046,7 +2046,7 @@ bool AfterLoadGame()
 						return false;
 					}
 
-					const Tunnel *t = new Tunnel(start_tile, end_tile, false);
+					const Tunnel *t = new Tunnel(start_tile, end_tile, TileHeight(start_tile), false);
 
 					SetTunnelIndex(start_tile, t->index);
 					SetTunnelIndex(end_tile, t->index);
@@ -2055,7 +2055,6 @@ bool AfterLoadGame()
 		}
 	}
 
-
 	/* Move the signal variant back up one bit for PBS. We don't convert the old PBS
 	 * format here, as an old layout wouldn't work properly anyway. To be safe, we
 	 * clear any possible PBS reservations as well. */