Added SDL_GL_RETAINED_BACKING to SDL_GLattr enum. Retained backing means the memory for color buffers, depth buffers, etc cannot be overwritten by other applications between frames. The default for this setting is 'on'. I wanted to add this because turning retained backing off on iPhone dramatically increases performance.

//
//  MyCustomView.h
//  SDL Custom View App
//
//  Created by Darrell Walisser on Fri Jul 18 2003.
//  Copyright (c) 2003 __MyCompanyName__. All rights reserved.
//

#import <AppKit/AppKit.h>


@interface MyCustomView : NSQuickDrawView
{
}

@end