Clang 5.0 fixes

- Added override keyword
- Removed inherited member variables

src/WorldStorage/WSSAnvil.h

@@ -51,7 +51,7 @@ class cWSSAnvil :
 public:
 
 	cWSSAnvil(cWorld * a_World, int a_CompressionFactor);
-	virtual ~cWSSAnvil();
+	virtual ~cWSSAnvil() override;
 
 protected:
 

src/WorldStorage/WorldStorage.h

@@ -62,7 +62,7 @@ class cWorldStorage :
 public:
 
 	cWorldStorage(void);
-	~cWorldStorage();
+	virtual ~cWorldStorage() override;
 
 	/** Queues a chunk to be loaded, asynchronously.
 	The callback, if specified, will be called with the result of the load operation. */