title: How to disable write in a Cell Handsontable and include one dropdown
body: <p>I made a fiddle with this example. <a href="http://jsfiddle.net/mk4wdaju/1/" rel="nofollow">Example with fiddle</a>.</p>
  
  <p>In the 4th colum there are some cells that I want to disable the write mode and activate the dropdown. Actually I have the dropdown and works well for me but I can keep writing in it and I want to disable this option. </p>
  
  <p>I just want only let the people choose one of these options. In this example the color or Bumber.</p>
  
  <p>I tried this including ReadOnly: </p>
  
  <pre><code>    {
        data: 'bumper',          
        type: 'dropdown',
        readOnly: true, 
        source: ['Red', 'Blue', 'Green']
      }
  </code></pre>
  
  <p>But (obviously) disable the whole cell and don't allow edit the cell with the dropdown.</p>