title: jquery chosen, empty String as option
body: <p>I´m using chosen.js for Dropdowns in a form on a grails-environment.
  I want the users to be able to select an empty option, but somehow it is ignored.
  There must be a possibility to do this? 
  Because the workaround to set an option like "select-none" and later in data-bindig make a if condition if select-none value= "" would be unpretty.</p>
  
  <p>to show my problem : </p>
  
  <p>for example this select :</p>
  
  <pre><code>&lt;g:select id="foo" data-placeholder="bar"  class="foo chzn-select" style="width: 245px;" tabindex="4" 
                      from="${['M', ' ', 'F']}" value="foo" name="titel"/&gt;
  </code></pre>
  
  <p>would return :</p>
  
  <p><img src="https://i.stack.imgur.com/pCLME.gif" alt="enter image description here"></p>
  
  <p>Sure this is a nice feature of chosen, but i guess my case is a common case and maybe someone of you already has a solution to override this behaviour</p>
  
  <p>thanks in advance</p>