title: UITableView content offset -64pt issue
body: <p>I am debugging table view and in my <code>-viewDidLoad</code> method I have:</p>
  
  <pre><code>&lt;UITableView: 0x7b394600; frame = (0 0; 1024 768); clipsToBounds = YES; gestureRecognizers = &lt;NSArray: 0x7983d2f0&gt;; layer = &lt;CALayer: 0x79836ca0&gt;; contentOffset: {0, 0}&gt;
  </code></pre>
  
  <p>but when I check the frame and content offset in <code>-viewDidAppear</code> method:</p>
  
  <pre><code>&lt;UITableView: 0x7ab79c00; frame = (0 0; 1024 768); clipsToBounds = YES; gestureRecognizers = &lt;NSArray: 0x7998f700&gt;; layer = &lt;CALayer: 0x7998f560&gt;; contentOffset: {0, -64}&gt;
  </code></pre>
  
  <p>I don't know how table get -64 for its offset.</p>
  
  <p>There is just sequence of methods view did load and then view did appear but content offset magically changed for me.</p>
  
  <p>What can be a reason?</p>
  
  <p>This is my viewDidLoad:</p>
  
  <pre><code>- (void)viewDidLoad
  {
      [super viewDidLoad];
  
      _theTableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height)];
  
      _theTableView.dataSource = self;
      _theTableView.delegate = self;
  
      [self.view addSubview:_theTableView];
  
      _theTableView.tableFooterView = [[UIView alloc] initWithFrame:CGRectZero];
  
      self.title = @"File Manager";
  }
  </code></pre>
  
  <p>I have navigation bar, but weird that I see my table as it should be without shifting. So looks perfect I see top cell and when I scroll to the bottom I see last cell. Even indicator says to me that content offset is 0. If I force set content offset {0, 0} then seems like first cell goes under navigation bar and vertical indicator starts not from the top but with some padding about 64 pt, but it's strange.</p>
  
  <p>I suppose this is because of status bar and navigation bar. But if hardcoded create my offset and frame, it does not help me. Seems like system does it form me automatically =)</p>