Created the TileSheet class

This is incomplete on it's own, but used as part of the whole map system,
it should work well. This class keeps track of various, seemingly
unrelated states, which are used as part of the larger map system.

Also, fixed Region's members being public.

editor/region.hpp

@@ -30,8 +30,6 @@
  * This class stores the tiles relative to it's own position, but
  * there are functions for referencing the tiles' absolute position.
  * These functions simply wrap the normal functions.
- *
- * TODO: This class needs to be thoroughly tested.
 */
 class Region {
 public:
@@ -89,7 +87,7 @@ public:
 	friend bool operator>(Region const& lhs, Region const& rhs);
 	friend bool operator==(Region const& lhs, Region const& rhs);
 
-public: //TMP
+private:
 	int const x;
 	int const y;
 	int const width;