Forward status bar appearance to child view controllers

[eladb]

- (UIViewController *)childViewControllerForStatusBarStyle
{
    if (self.childViewControllers.count == 0) {
        return [super childViewControllerForStatusBarStyle];
    }

    return self.childViewControllers[self.childViewControllers.count - 1];
}

- (UIViewController *)childViewControllerForStatusBarHidden
{
    if (self.childViewControllers.count == 0) {
        return [super childViewControllerForStatusBarStyle];
    }

    return self.childViewControllers[self.childViewControllers.count - 1];
}