iOS5/6 shouldAutorotateToInterfaceOrientation compatibility

gistfile1.m

- (BOOL)shouldAutorotate
{
    return YES;
}

- (NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationMaskAllButUpsideDown;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    if ([self respondsToSelector:@selector(shouldAutorotate)] &&
        [self respondsToSelector:@selector(supportedInterfaceOrientations)]) {
        // delegate to iOS6 compatible methods.
        return [self shouldAutorotate] && ((1 << interfaceOrientation) & [self supportedInterfaceOrientations]);
    }
    else {
        return [self shouldAutorotateToInterfaceOrientation:interfaceOrientation];
    }
}