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/JavaIntHash.h

@@ -13,9 +13,9 @@ struct IntKeyHash
 	{
 		int h = k;
         h += ~(h << 9);
-        h ^=  (((unsigned int)h) >> 14);
+        h ^=  (static_cast<unsigned int>(h) >> 14);
         h +=  (h << 4);
-        h ^=  (((unsigned int)h) >> 10);
+        h ^=  (static_cast<unsigned int>(h) >> 10);
 		return h;
 	}
 };