(svn r10122) -Codechange: Add a CountBitsSet function and use it to replace some less efficient loops.

src/functions.h

@@ -147,9 +147,11 @@ Town *ClosestTownFromTile(TileIndex tile, uint threshold);
 void ChangeTownRating(Town *t, int add, int max);
 
 uint GetTownRadiusGroup(const Town* t, TileIndex tile);
-int FindFirstBit(uint32 x);
 void ShowHighscoreTable(int difficulty, int8 rank);
 
+int FindFirstBit(uint32 x);
+int CountBitsSet(uint32 value);
+
 void AfterLoadTown();
 void UpdatePatches();
 void AskExitGame();