title: [iPhone]How to customize header of Section in grouped TableView?
body: <p>To customize cell, we implement class inherit UITableViewCell. Now, to customize header of Section in grouped UITableView (same to below picture), how to do? Please guide to me!<br>
  <img src="https://farm5.static.flickr.com/4007/4273969640_8c59907977.jpg" alt="alt text"></p>