title: DeselectAll doesn't work for Bootstrap-select
body: <p>Here is example what i try, but didn't work.</p>
  
  <p><a href="http://jsfiddle.net/re8tevoc/10/" rel="noreferrer">JsFiddle</a></p>
  
  <p>What i expect : on button click all options will be unselected.</p>
  
  <p>I try with "refresh" and "render" but also didn't help.</p>
  
  <pre><code> &lt;select class="selectpicker" multiple title="Not changable text" data-count-selected-text="Not changable text"&gt;
           &lt;option&gt;Mustard&lt;/option&gt;
           &lt;option&gt;Ketchup&lt;/option&gt;
           &lt;option&gt;Relish&lt;/option&gt;
   &lt;/select&gt;
  
  &lt;button id="f1"&gt;ggg&lt;/button&gt;
  
  $('#f1').click(function(){
     $('.selectpicker').selectpicker('deselectAll');
  });
  </code></pre>
  
  <hr>
  
  <p>UPDATE : code doesn't work if select is closed. In case it's open - all is good</p>