qtmain_win.cpp: Remove unused header files

1. Removed all Qt header files and make it a pure win32 project because it doesn't use any Qt features.
2. According to MSDN, CommandLineToArgvW is in shellapi.h, so replace ShlObj.h with it.

Change-Id: I3daacb97f34664ac36f8e887a2c31d38f611b16e
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

src/winmain/qtmain_win.cpp

@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2019 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the Windows main function of the Qt Toolkit.
@@ -48,12 +48,8 @@
 **
 ****************************************************************************/
 
-#include "qt_windows.h"
-#include "qbytearray.h"
-#include "qstring.h"
-#include "qvector.h"
-
-#include <shlobj.h>
+#include <windows.h>
+#include <shellapi.h>
 
 /*
   This file contains the code in the qtmain library for Windows.
@@ -64,9 +60,6 @@
   invoked.
 */
 
-QT_USE_NAMESPACE
-
-
 #if defined(QT_NEEDS_QMAIN)
 int qMain(int, char **);
 #define main qMain

src/winmain/winmain.pro

@@ -21,8 +21,8 @@ mingw: DEFINES += QT_NEEDS_QMAIN
 winrt {
     SOURCES = qtmain_winrt.cpp
 } else {
+    CONFIG -= qt
     SOURCES = qtmain_win.cpp
-
     LIBS += -lshell32
 }