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/OcelotAttackGoal.cpp

@@ -21,14 +21,14 @@ OcelotAttackGoal::OcelotAttackGoal(Mob *mob)
 bool OcelotAttackGoal::canUse()
 {
 	shared_ptr<LivingEntity> bestTarget = mob->getTarget();
-	if (bestTarget == NULL) return false;
+	if (bestTarget == nullptr) return false;
 	target = weak_ptr<LivingEntity>(bestTarget);
 	return true;
 }
 
 bool OcelotAttackGoal::canContinueToUse()
 {
-	if (target.lock() == NULL || !target.lock()->isAlive()) return false;
+	if (target.lock() == nullptr || !target.lock()->isAlive()) return false;
 	if (mob->distanceToSqr(target.lock()) > 15 * 15) return false;
 	return !mob->getNavigation()->isDone() || canUse();
 }