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/PlayerAbilitiesPacket.h

@@ -42,9 +42,9 @@ public:
 	float getWalkingSpeed();
 	void setWalkingSpeed(float walkingSpeed);
 	bool canBeInvalidated();
-	bool isInvalidatedBy(shared_ptr<Packet> packet);
+	bool isInvalidatedBy(std::shared_ptr<Packet> packet);
 
 public:
-	static shared_ptr<Packet> create() { return shared_ptr<Packet>(new PlayerAbilitiesPacket()); }
+	static std::shared_ptr<Packet> create() { return std::shared_ptr<Packet>(new PlayerAbilitiesPacket()); }
 	virtual int getId() { return 202; }
 };