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/Windows64/KeyboardMouseInput.cpp

@@ -288,7 +288,7 @@ void KeyboardMouseInput::SetMouseGrabbed(bool grabbed)
 	else if (!grabbed && !m_cursorHiddenForUI && g_hWnd)
 	{
 		while (ShowCursor(TRUE) < 0) {}
-		ClipCursor(NULL);
+		ClipCursor(nullptr);
 	}
 }
 
@@ -317,7 +317,7 @@ void KeyboardMouseInput::SetCursorHiddenForUI(bool hidden)
 	else if (!hidden && !m_mouseGrabbed && g_hWnd)
 	{
 		while (ShowCursor(TRUE) < 0) {}
-		ClipCursor(NULL);
+		ClipCursor(nullptr);
 	}
 }
 
@@ -347,13 +347,13 @@ void KeyboardMouseInput::SetWindowFocused(bool focused)
 		else
 		{
 			while (ShowCursor(TRUE) < 0) {}
-			ClipCursor(NULL);
+			ClipCursor(nullptr);
 		}
 	}
 	else
 	{
 		while (ShowCursor(TRUE) < 0) {}
-		ClipCursor(NULL);
+		ClipCursor(nullptr);
 	}
 }