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/HatchetItem.h

@@ -11,5 +11,5 @@ private:
 public:
 	static void staticCtor();
 	HatchetItem(int id, const Tier *tier);
-	virtual float getDestroySpeed(shared_ptr<ItemInstance> itemInstance, Tile *tile);	// 4J - brought forward from 1.2.3
+	virtual float getDestroySpeed(std::shared_ptr<ItemInstance> itemInstance, Tile *tile);	// 4J - brought forward from 1.2.3
 };