title: CakePHP multiple select "selected" is not working
body: <p>I have a multiple select input in my edit form:-</p>
  
  <pre><code>&lt;?php echo $this-&gt;Form-&gt;input('Article.tags', array('type' =&gt; 'select', 'multiple' =&gt; true, 'options' =&gt; $tags, 'selected' =&gt; array($selected))); ?&gt;
  </code></pre>
  
  <p>When echo-ed, the <strong><code>$selected</code></strong> variable will look like this:-</p>
  
  <pre><code>"MySQL", "PHP"
  </code></pre>
  
  <p>However, the input does not automatically select the option that matches the tag.</p>
  
  <p>However, when I manually put in the selected option, it will automatically select that two option; e.g.</p>
  
  <pre><code>&lt;?php echo $this-&gt;Form-&gt;input('Article.tags', array('type' =&gt; 'select', 'multiple' =&gt; true, 'options' =&gt; $tags, 'selected' =&gt; array("MySQL", "PHP"))); ?&gt;
  </code></pre>
  
  <p>Is there anyway to fix this? Thanks.</p>