title: jQuery.appear to fire only when the entire element in is viewport
body: <p>I'm currently using <a href="https://github.com/morr/jquery.appear" rel="nofollow" title="Click here to view">jQuery.appear</a> to change the class of elements as they come into the viewport. The plugin works great, except that it fires right as the top of the element comes into view. I am wanting to adapt it so it only fires when the entire element is inside the viewport, or near to being.</p>
  
  <p>CODE:</p>
  
  <pre><code>$('someselector').appear();
  $('someselector').on('appear', function() {
      $(this).removeClass('on').addClass('off');
      $(this).siblings().removeClass('off').addClass('on');
  });
  </code></pre>