Reading and writing saved games now uses the new tagfile system.

This should avoid any format inconsistencies, like missing newlines and the like.
Although a basic save and load works, there may still be some issues with the format.
This probably renders older saved games incompatible.
The format is mostly the same, but there are a few small changes
in the name of making the format more uniform.

src/scenario/town.hpp

@@ -113,8 +113,6 @@ public:
 	explicit cTown(cScenario& scenario, size_t dim);
 	void import_legacy(legacy::town_record_type& old);
 	void reattach(cScenario& to);
-	void writeTerrainTo(std::ostream& file);
-	void readTerrainFrom(std::istream& file);
 	// Work with the item_taken bitset
 	bool is_item_taken(size_t i) const;
 	void clear_items_taken();