Ensuring scroll offset is sensible after rotate

[sobri909]

UIScrollView doesn't automatically take into account contentSize changes on rotate, so can leave you at an offset that shows different content.

If you're using the boxProvider system, you can now use saveScrollOffset and restoreScrollOffset to keep things looking sensible after rotate.

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)orient
      duration:(NSTimeInterval)duration {
    [super willRotateToInterfaceOrientation:orient duration:duration];
    [self.scroller saveScrollOffset];
}

- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)orient
      duration:(NSTimeInterval)duration {
    [super willAnimateRotationToInterfaceOrientation:orient duration:duration];
    [self.scroller restoreScrollOffset];
}