title: Select2 with Twitter Bootstrap 3 / Dropdown wrong width
body: <p>I want to use select2.js in combination with twitter bootstrap 3.
  Everything works fine so far, except the fact, that the Drop-Down container has not the same width as the select container itself.</p>
  
  <p>By resizing the window this phenomen appears and disappears.</p>
  
  <p>Here is a picture that shows the issue <img src="https://i.stack.imgur.com/xtOoT.png" alt="width issue"></p>
  
  <p>And here is the jsfiddle where you can try the resizing. (Tested it with IE 11 and FF 26)
  <a href="http://jsfiddle.net/AgwA4/" rel="noreferrer">jsfiddle</a></p>
  
  <p>And here also the code:</p>
  
  <pre><code>&lt;link rel="stylesheet" href="http://getbootstrap.com/dist/css/bootstrap.min.css"&gt;
  &lt;link rel="stylesheet" href="http://cdn.jsdelivr.net/select2/3.4.5/select2.css"&gt;
  
  &lt;div class="container"&gt; 
      &lt;div class="row"&gt;
          &lt;div class="col-xs-3"&gt;
              &lt;select style="width:100%" class="select2"&gt;
                  &lt;optgroup label="Test-group"&gt;    
                      &lt;option&gt;test1&lt;/option&gt;
                      &lt;option&gt;test2&lt;/option&gt;
                  &lt;/optgroup&gt;
              &lt;/select&gt;
            &lt;/div&gt;    
      &lt;div class="col-xs-3"&gt;
              &lt;select style="width:100%" class="select2"&gt;
                  &lt;optgroup label="Test-group"&gt;    
                      &lt;option&gt;test1&lt;/option&gt;
                      &lt;option&gt;test2&lt;/option&gt;
                  &lt;/optgroup&gt;
              &lt;/select&gt;
            &lt;/div&gt;
          &lt;div class="col-xs-3"&gt;
              &lt;select style="width:100%" class="select2"&gt;
                  &lt;optgroup label="Test-group"&gt;    
                      &lt;option&gt;test1&lt;/option&gt;
                      &lt;option&gt;test2&lt;/option&gt;
                  &lt;/optgroup&gt;
              &lt;/select&gt;
            &lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I tried to find a solution for hours now, but I can't find a solution for that issue.</p>
  
  <p>Thank you and best regards</p>