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/AgableMob.h

@@ -13,13 +13,13 @@ private:
 public:
 	AgableMob(Level *level);
 
-	virtual bool interact(shared_ptr<Player> player);
+	virtual bool interact(std::shared_ptr<Player> player);
 
 protected:
 	virtual void defineSynchedData();
 
 public:
-	virtual shared_ptr<AgableMob> getBreedOffspring(shared_ptr<AgableMob> target) = 0;
+	virtual std::shared_ptr<AgableMob> getBreedOffspring(std::shared_ptr<AgableMob> target) = 0;
 	virtual int getAge();
 	virtual void setAge(int age);
 	virtual void addAdditonalSaveData(CompoundTag *tag);