Port of Duke Nukem 3D

This ports Fabien Sanglard's Chocolate Duke to run on a version of SDL
for Rockbox.

Change-Id: I8f2c4c78af19de10c1633ed7bb7a997b43256dd9

apps/plugins/duke3d.c

@@ -0,0 +1,31 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2017 Franklin Wei
+ *
+ * Duke3D stub loader.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "plugin.h"
+
+#include "lib/overlay.h"
+
+/* this is the plugin entry point */
+enum plugin_status plugin_start(const void* parameter)
+{
+    return run_overlay(parameter, PLUGIN_GAMES_DIR "/duke3d.ovl", "Duke3D");
+}