(svn r1751) - Feature: New PathFinder (NPF).

- Supports trains, road vehicles and ships.
	- Uses A* pathfinding (same codebase as the new ai).
	- Currently unlimited search depth, so might perform badly on large maps/networks (especially ships).
	- Will always find a route if there is one.
	- Allows custom penalties for obstacles to be set in openttd.cfg (npf_ values).
	- With NPF enabled, ships can have orders that are very far apart. Be careful, this will break (ships get lost) when the old pathfinder is used again.
- Feature: Disabling 90 degree turns for trains and ships.
	- Requires NPF to be enabled.
	- Ships and trains can no longer make weird 90 degree turns on tile borders.
- Codechange: Removed table/directions.h.
	- table/directions.h contained ugly static tables but was included more than once. The tables, along with a few new ones are in npf.[ch] now. Better suggestions for a location?
- Fix: Binary heap in queue.c did not allocate enough space, resulting in a segfault.
- Codechange: Rewritten FindFirstBit2x64, added KillFirstBit2x64.
- Codechange: Introduced constant INVALID_TILE, to replace the usage of 0 as an invalid tile. Also replaces TILE_WRAPPED.
- Codechange: Moved TileAddWrap() to map.[ch] 
- Add TileIndexDiffCByDir(), TileIndexDiffCByDir(). 
- Codechange: Moved IsTrainStationTile() to station.h
- Add: IsRoadStationTile() and GetRoadStationDir().

station_cmd.c

@@ -16,7 +16,7 @@
 #include "player.h"
 #include "airport.h"
 #include "sprite.h"
-#include "table/directions.h"
+#include "npf.h"
 
 // FIXME -- need to be embedded into Airport variable. Is dynamically
 // deducteable from graphics-tile array, so will not be needed
@@ -2277,10 +2277,6 @@ static void ClickTile_Station(uint tile)
 	}
 }
 
-static inline bool IsTrainStationTile(uint tile) {
-	return IsTileType(tile, MP_STATION) && IS_BYTE_INSIDE(_map5[tile], 0, 8);
-}
-
 static const byte _enter_station_speedtable[12] = {
 	215, 195, 175, 155, 135, 115, 95, 75, 55, 35, 15, 0
 };