title: Using "role:'annotation'" to place text vertically
body: <p>I have used the <code>rotate:90</code>, styles and other attemps.</p>
  
  <pre><code>data.addColumn({type:'string', role:'annotation'});
  </code></pre>
  
  <p>Please see <a href="http://i.stack.imgur.com/1qQPr.png" rel="nofollow">image</a>:</p>
  
  <p>There is the "<code>annotations:{style:'line'}</code>" option but it does create a unsightly middle centered line.. That's not what I want.. I just want to rotate the text 90º.</p>