shared_ptr -> std::shared_ptr

This is one of the first commits in a plan to remove all `using namespace std;` lines in the entire codebase as it is considered anti-pattern today.

Minecraft.World/FenceTile.h

@@ -10,7 +10,7 @@ private:
 public:
 	FenceTile(int id, const wstring &texture, Material *material);
 	virtual AABB *getAABB(Level *level, int x, int y, int z);
-	virtual void updateShape(LevelSource *level, int x, int y, int z, int forceData = -1, shared_ptr<TileEntity> forceEntity = shared_ptr<TileEntity>()); // 4J added forceData, forceEntity param
+	virtual void updateShape(LevelSource *level, int x, int y, int z, int forceData = -1, std::shared_ptr<TileEntity> forceEntity = std::shared_ptr<TileEntity>()); // 4J added forceData, forceEntity param
 	virtual bool blocksLight();
 	virtual bool isSolidRender(bool isServerLevel = false);
 	virtual bool isCubeShaped();