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/PotatoTile.cpp

@@ -46,7 +46,7 @@ void PotatoTile::spawnResources(Level *level, int x, int y, int z, int data, flo
 	{
 		if (level->random->nextInt(50) == 0)
 		{
-			popResource(level, x, y, z, shared_ptr<ItemInstance>(new ItemInstance(Item::potatoPoisonous)));
+			popResource(level, x, y, z, std::make_shared<ItemInstance>(Item::potatoPoisonous));
 		}
 	}
 }