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/HopperMenu.cpp

@@ -35,7 +35,7 @@ shared_ptr<ItemInstance> HopperMenu::quickMoveStack(shared_ptr<Player> player, i
 {
 	shared_ptr<ItemInstance> clicked = nullptr;
 	Slot *slot = slots.at(slotIndex);
-	if (slot != NULL && slot->hasItem())
+	if (slot != nullptr && slot->hasItem())
 	{
 		shared_ptr<ItemInstance> stack = slot->getItem();
 		clicked = stack->copy();