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/WoodSlabTile.cpp

@@ -33,7 +33,7 @@ int WoodSlabTile::getResource(int data, Random *random, int playerBonusLevel)
 
 shared_ptr<ItemInstance> WoodSlabTile::getSilkTouchItemInstance(int data)
 {
-	return shared_ptr<ItemInstance>(new ItemInstance(Tile::woodSlabHalf, 2, data & TYPE_MASK));
+	return std::make_shared<ItemInstance>(Tile::woodSlabHalf, 2, data & TYPE_MASK);
 }
 
 int WoodSlabTile::getAuxName(int auxValue)