title: jQuery fadeIn ignores duration parameter passed to a directive
body: <p>I have the following directive:</p>
  
  <pre><code>app.directive('showonhoverparent',
    function() {
  
      return {
        link : function(scope, element, attrs) {
          element.parent().bind('mouseenter', function() {
            console.log(attrs.showonhoverparent);
            element.fadeIn(attrs.showonhoverparent);
          });
          element.parent().bind('mouseleave', function() {
            element.fadeOut(attrs.showonhoverparent);
          });
        }
      };
    }
  );
  </code></pre>
  
  <p>And I use it like this in the html:</p>
  
  <pre><code>&lt;div class="img-text" showonhoverparent="2000"&gt;{{image.title}}&lt;/div&gt;
  </code></pre>
  
  <p>or:</p>
  
  <pre><code>&lt;div class="img-text" showonhoverparent="'slow'"&gt;{{image.title}}&lt;/div&gt;
  </code></pre>
  
  <p>For some reason, no matter what I pass as the as the attribute value, the fadein/out speed id always the default speed, as if no parameter is passed to it! any ideas why?</p>