Project modernization (#630)

* 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

Minecraft.World/HurtByTargetGoal.cpp

@@ -30,7 +30,7 @@ void HurtByTargetGoal::start()
 		{
 			shared_ptr<PathfinderMob> other = dynamic_pointer_cast<PathfinderMob>(it);
 			if (this->mob->shared_from_this() == other) continue;
-			if (other->getTarget() != NULL) continue;
+			if (other->getTarget() != nullptr) continue;
 			if (other->isAlliedTo(mob->getLastHurtByMob())) continue; // don't target allies
 			other->setTarget(mob->getLastHurtByMob());
 		}