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/ByteTag.h

@@ -23,7 +23,7 @@ public:
 	{
 		if (Tag::equals(obj))
 		{
-			ByteTag *o = (ByteTag *) obj;
+			ByteTag *o = static_cast<ByteTag *>(obj);
 			return data == o->data;
 		}
 		return false;