Prevent iOS 7 from messing with our contentInset.

PSTViewController.m

- (void)viewDidLoad {
    [super viewDidLoad];

    // This view exists purely so that iOS 7 stops messing with our PSPDFScrollView.
    // If this doesn't exist and the parent didn't set `automaticallyAdjustsScrollViewInsets` to NO, then the view doesn't stay fixed anymore.
    // This is better than enforcing disabling this property on the parent - since we don't even know who our parent is.
    UIView *fakeView = [[UIView alloc] initWithFrame:CGRectZero];
    fakeView.backgroundColor = UIColor.clearColor;
    fakeView.userInteractionEnabled = NO;
    [self.view addSubview:fakeView];

...
}