Missing config files

 ...and add functionality on the Director to override the default values
    from the config file.
    
    Supported values:
    
     - cocos2d.x.fps
     - cocos2d.x.display_fps
     - cocos2d.x.gl.projection
     - cocos2d.x.texture.pixel_format_for_png
     - cocos2d.x.texture.pvrv2_has_alpha_premultiplied
    
    If the "config.plist" file is not present, or some keys are not present,
    the default values are going to be used
    
    IMPORTANT:
     The folder "samples/Cpp/TestCpp/Resources/configs" needs to be added
     in the Android, Linux, Win32 projects.
     Already added in OS X and iOS Xcode projects.