Merge branch 'master' into jgrpp

# Conflicts:
#	src/industry_cmd.cpp
#	src/landscape.cpp
#	src/object_cmd.cpp
#	src/rail_cmd.cpp
#	src/script/api/script_tile.cpp
#	src/table/settings/difficulty_settings.ini
#	src/table/settings/world_settings.ini
#	src/terraform_cmd.cpp
#	src/tilearea_type.h
#	src/tree_cmd.cpp
#	src/tree_cmd.h
#	src/tree_gui.cpp
#	src/water_cmd.cpp

src/bitmap_type.h

@@ -132,9 +132,9 @@ public:
 		return *this;
 	}
 
-	virtual TileIterator *Clone() const
+	virtual std::unique_ptr<TileIterator> Clone() const
 	{
-		return new BitmapTileIterator(*this);
+		return std::make_unique<BitmapTileIterator>(*this);
 	}
 };