title: UILabel in a grouped table view's header doesn't wrap text
body: <p>I have a label whose text is longer that the table view's header containing it, so I want the label to be split into N lines according to the width available. This is my code:</p>
  
  <pre><code>- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
  {
    if (section == 1) {
      UIView *wrapper = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.tableView.frame.size.width, 100)];
      [wrapper setBackgroundColor:[UIColor clearColor]];
  
      UILabel *textLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, self.tableView.frame.size.width, 100)];
      textLabel.text = NSLocalizedString(@"This is supposed to be a very long text that may fill several lines", @"");
      [textLabel setLineBreakMode:UILineBreakModeWordWrap];
      [textLabel setNumberOfLines:0];
      [wrapper addSubview:textLabel];
  
      return wrapper;
    }
    else
      return nil;
  }
  </code></pre>
  
  <p>However, the label is in a single line and I can't see the end of the text. What am I missing?</p>
  
  <p>Thanks!</p>