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.Client/RenameWorldScreen.cpp

@@ -8,7 +8,7 @@
 
 RenameWorldScreen::RenameWorldScreen(Screen *lastScreen, const wstring& levelId)
 {
-	nameEdit = NULL;
+	nameEdit = nullptr;
     this->lastScreen = lastScreen;
     this->levelId = levelId;
 }