title: Custom data attribute not working inside <select> tag
body: <p>See this code:</p>
  
  <pre><code>&lt;!DOCTYPE HTML&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;meta charset="UTF-8"&gt;
          &lt;script src="Template/js/jquery-1.9.0.min.js" &gt;&lt;/script&gt;
          &lt;script&gt;
          $(document).ready(function(){
  
              $(".myselect").change(function(){
                  alert( $(this).attr('data-spacing') );
              });
  
          });
          &lt;/script&gt;
      &lt;/head&gt;
      &lt;body&gt;
      &lt;select name="type" class="myselect"&gt;
          &lt;option data-spacing="001" value="" selected &gt;Select A Camera&lt;/option&gt;
          &lt;option data-spacing="002" value="Nicon_D500"&gt;Nicon D500&lt;/option&gt;
          &lt;option data-spacing="004" value="Nicon_D600"&gt;Nicon D600&lt;/option&gt;
          &lt;option data-spacing="003" value="Canon_S900"&gt;Canon S900&lt;/option&gt;
      &lt;/select&gt;
  
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>The <code>data-custom</code> attribute is working for anything,<br>
  but it's not working for <code>&lt;select&gt;</code> and <code>&lt;option&gt;</code> tags.</p>
  
  <p>This source code returns "Undefined"<br>
  Please help me.</p>