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/FenceTile.cpp

@@ -122,7 +122,7 @@ bool FenceTile::connectsTo(LevelSource *level, int x, int y, int z)
 		return true;
 	}
 	Tile *tileInstance = Tile::tiles[tile];
-	if (tileInstance != NULL)
+	if (tileInstance != nullptr)
 	{
 		if (tileInstance->material->isSolidBlocking() && tileInstance->isCubeShaped())
 		{