Merge branch 'master' into jgrpp

# Conflicts:
#	src/debug.cpp
#	src/saveload/afterload.cpp
#	src/saveload/saveload.cpp
#	src/settings_type.h
#	src/town_cmd.cpp
#	src/window.cpp

src/map_func.h

@@ -148,7 +148,7 @@ static inline uint ScaleByMapSize1D(uint n)
  * An offset value between to tiles.
  *
  * This value is used for the difference between
- * to tiles. It can be added to a tileindex to get
+ * two tiles. It can be added to a tileindex to get
  * the resulting tileindex of the start tile applied
  * with this saved difference.
  *
@@ -363,6 +363,18 @@ static inline TileIndexDiff TileOffsByDir(Direction dir)
 	return ToTileIndexDiff(_tileoffs_by_dir[dir]);
 }
 
+/**
+ * Adds a Direction to a tile.
+ *
+ * @param tile The current tile
+ * @param dir The direction in which we want to step
+ * @return the moved tile
+ */
+static inline TileIndex TileAddByDir(TileIndex tile, Direction dir)
+{
+	return TILE_ADD(tile, TileOffsByDir(dir));
+}
+
 /**
  * Adds a DiagDir to a tile.
  *