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/Common/XUI/XUI_Ctrl_SlotItemCtrlBase.h

@@ -9,7 +9,7 @@ class ItemInstance;
 class SlotControlUserDataContainer
 {
 public:
-	SlotControlUserDataContainer() : slot( NULL ), hProgressBar( NULL ), m_iPad( -1 ), m_fAlpha(1.0f) {};
+	SlotControlUserDataContainer() : slot( nullptr ), hProgressBar( nullptr ), m_iPad( -1 ), m_fAlpha(1.0f) {};
 	Slot* slot;
 	HXUIOBJ hProgressBar;
 	float m_fAlpha;