add null loading window (not even SDL)

stepmania/src/arch/LoadingWindow/LoadingWindow_Null.h

@@ -0,0 +1,25 @@
+#ifndef LOADING_WINDOW_NULL_H
+#define LOADING_WINDOW_NULL_H
+
+/* Loading window using a Windows dialog. */
+#include "LoadingWindow.h"
+
+class LoadingWindow_Null: public LoadingWindow {
+public:
+	LoadingWindow_Win32() { }
+	~LoadingWindow_Win32() { }
+
+	void SetText(CString str) { }
+	void Paint() { }
+};
+
+#undef ARCH_LOADING_WINDOW
+#define ARCH_LOADING_WINDOW LoadingWindow_Null
+
+#endif
+
+/*
+ * Copyright (c) 2003 by the person(s) listed below.  All rights reserved.
+ *
+ * Glenn Maynard
+ */