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/Explosion.h

@@ -36,7 +36,7 @@ public:
 	void explode();
 
 public:
-	void finalizeExplosion(bool generateParticles, vector<TilePos> *toBlowDirect = NULL);   // 4J - added toBlow parameter
+	void finalizeExplosion(bool generateParticles, vector<TilePos> *toBlowDirect = nullptr);   // 4J - added toBlow parameter
 	playerVec3Map *getHitPlayers();
 	Vec3 *getHitPlayerKnockback( shared_ptr<Player> player );
 	shared_ptr<LivingEntity> getSourceMob();