Modernize project codebase (#906)

* Fixed boats falling and a TP glitch #266

* Replaced every C-style cast with C++ ones

* Replaced every C-style cast with C++ ones

* Fixed boats falling and a TP glitch #266

* Updated NULL to nullptr and fixing some type issues

* Modernized and fixed a few bugs

- Replaced most instances of `NULL` with `nullptr`.
- Replaced most `shared_ptr(new ...)` with `make_shared`.
- Removed the `nullptr` macro as it was interfering with the actual nullptr keyword in some instances.

* Fixing more conflicts

* Replace int loops with size_t and start work on overrides

* Add safety checks and fix a issue with vector going OOR

Minecraft.World/MovePlayerPacket.h

@@ -27,7 +27,7 @@ public:
 	virtual bool isInvalidatedBy(shared_ptr<Packet> packet);
 
 public:
-	static shared_ptr<Packet> create() { return shared_ptr<Packet>(new MovePlayerPacket()); }
+	static shared_ptr<Packet> create() { return std::make_shared<MovePlayerPacket>(); }
 	virtual int getId() { return 10; }
 };
 
@@ -42,7 +42,7 @@ public:
 	virtual int getEstimatedSize();
 
 public:
-	static shared_ptr<Packet> create() { return shared_ptr<Packet>(new MovePlayerPacket::PosRot()); }
+	static shared_ptr<Packet> create() { return std::make_shared<MovePlayerPacket::PosRot>(); }
 	virtual int getId() { return 13; }
 };
 
@@ -57,7 +57,7 @@ public:
 	virtual int getEstimatedSize();
 
 public:
-	static shared_ptr<Packet> create() { return shared_ptr<Packet>(new MovePlayerPacket::Pos()); }
+	static shared_ptr<Packet> create() { return std::make_shared<MovePlayerPacket::Pos>(); }
 	virtual int getId() { return 11; }
 
 };
@@ -72,7 +72,7 @@ public:
 	virtual void write(DataOutputStream *dos);
 	virtual int getEstimatedSize();
 public:
-	static shared_ptr<Packet> create() { return shared_ptr<Packet>(new MovePlayerPacket::Rot()); }
+	static shared_ptr<Packet> create() { return std::make_shared<MovePlayerPacket::Rot>(); }
 	virtual int getId() { return 12; }
 
 };