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/MobSpawnerTile.cpp

@@ -9,7 +9,7 @@ MobSpawnerTile::MobSpawnerTile(int id) : BaseEntityTile(id, Material::stone, isS
 
 shared_ptr<TileEntity> MobSpawnerTile::newTileEntity(Level *level)
 {
-	return shared_ptr<MobSpawnerTileEntity>( new MobSpawnerTileEntity() );
+	return std::make_shared<MobSpawnerTileEntity>();
 }
 
 int MobSpawnerTile::getResource(int data, Random *random, int playerBonusLevel)