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.

/*
 *  jump.h
 *  iPodSDL
 *
 *  Created by Holmes Futrell on 7/2/08.
 *  Copyright 2008 __MyCompanyName__. All rights reserved.
 *
 */

#include "setjmp.h"

extern jmp_buf* jump_env();
extern int canJump;