title: Adding "data-" attributes with select2
body: <p>I've seen a lot examples of <code>Select2</code> option tags set with "data-" attributes and I would like to do it.</p>
  
  <p>I'm using ajax to get the data. I get the <code>ID</code> and the <code>TEXT</code> needed to build the select. </p>
  
  <blockquote>
    <p>But how can I add more attributes to it?</p>
  </blockquote>
  
  <p>I just didn't find the way to add them.</p>
  
  <pre><code>$(element).select2({
      placeholder: 'Select one...',
      width: '100%',
      minimumInputLength: 2,
      ajax: {
          url: '/my/url',
          dataType: 'json',
          data: function(params) {
              return {
                  q: params.term,
                  page: params.page
              };
           },
           processResults: function(data, page) {
               console.log(data);
               return {
                   results: data
               };
           },
           cache: true
       }
   });
  </code></pre>