(svn r3078) Some more stuff, which piled up:

- const, whitespace, indentation, bracing, GB/SB, pointless casts
- use the trinary operator where appropriate
- data types (uint[] -> AcceptedCargo, ...)
- if cascade -> switch
- if (ptr) -> if (ptr != NULL)
- DeMorgan's Law
- Fix some comments
- 0 -> '\0', change magic numbers to symbolic constants

gui.h

@@ -42,7 +42,7 @@ void PlaceProc_BuyLand(TileIndex tile);
 void ShowPlayerTrains(PlayerID player, StationID station);
 void ShowTrainViewWindow(Vehicle *v);
 void ShowTrainDetailsWindow(Vehicle *v);
-void ShowOrdersWindow(Vehicle *v);
+void ShowOrdersWindow(const Vehicle* v);
 
 void ShowRoadVehViewWindow(Vehicle *v);
 
@@ -95,7 +95,7 @@ void ShowEstimatedCostOrIncome(int32 cost, int x, int y);
 void ShowErrorMessage(StringID msg_1, StringID msg_2, int x, int y);
 
 void DrawStationCoverageAreaText(int sx, int sy, uint mask,int rad);
-void CheckRedrawStationCoverage(Window *w);
+void CheckRedrawStationCoverage(const Window* w);
 
 void ShowSmallMap(void);
 void ShowExtraViewPortWindow(void);