title: Custom rounded corners for first and last cell in a grouped UITableView
body: <p>My iPhone app is currently displaying a grouped table with 2 sections. I tried to change the radius of the rounded corners on the first and last cells of each section (or on the same cell in the case of sections with just one row) using:</p>
  
  <pre><code>cell.layer.cornerRadius = 4;
  </code></pre>
  
  <p>or acting on the whole tableview:</p>
  
  <pre><code>self.tableView.layer.cornerRadius = 4;
  </code></pre>
  
  <p>but no luck...Of course I've imported <em>QuartzCore</em> before performing this operation. It looks like it's possible to customise the corners only when the table is displayed with plain style.</p>
  
  <p>The ideal solution would be to customise top corners in the first one and bottom corners in the last.</p>
  
  <p>Any suggestions?</p>