Gnoga Native Mac OS X App Support Added

[David Botton <david@botton.com>]

http://www.gnoga.com

See docs/native_mac_apps.md for more information, but here is a summary:

1. Create a singleton app using Gnoga
2. Make native support for Mac using:
     make native_osx
3. Copy your project's individual bin, js, etc. directories to deps/MacGap2/public
4. Modify the index.html file in deps/MacGap2/public to contain the following lines:

   ``` html
   <script type="text/javascript" charset="utf-8">
   var p = MacGap.resourcePath + "/public/bin/YOUR_GNOGA_APP_NAME";
   MacGap.launch (p);
   window.open("http://127.0.0.1:8080","_self")
   </script>
   ```

   Note: The index.html page can be used to display some sort of "loading"
         message if desired.
5. From the deps directory run - open MacGap2/MG.xcodeproj/
6. Build as you would any native Mac OS X application for XCode