title: CasperJS loses select box vaue after submit
body: <p>I have that select form:</p>
  
  <pre><code>&lt;div class="row"&gt;
    &lt;div class="col-xs-18 form-group"&gt;
    &lt;label class="text-base" for="Gender"&gt;Geschlecht&lt;/label&gt;
      &lt;select id="Gender" class="form-control" data-bind="value: gender, hasFocus: gender.focused, css: { 'has-error': showError(gender) }" name="Gender"&gt;
        &lt;option value="" selected="selected"&gt;Ausw&amp;auml;hlen...&lt;/option&gt;
        &lt;option value="m"&gt;M&amp;auml;nnlich&lt;/option&gt;
        &lt;option value="f"&gt;Weiblich&lt;/option&gt;
        &lt;option value="u"&gt;Keine Angabe&lt;/option&gt;
     &lt;/select&gt;
    &lt;div class="alert alert-error" aria-atomic="true" aria-relevant="text" aria-live="assertive" data-bind="errorMessage: gender, visible: showError(gender)" style="display: none;"&gt;Diese Informationen sind erforderlich.&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>and filled it this way: </p>
  
  <pre><code>casper.then(function() {
      this.evaluate(function(anrede_inside) {
          document.querySelector('select#Gender').value = anrede_inside;
      }, anrede);
  });
  </code></pre>
  
  <p>so far its working great. but when i submit the page i get an error message that i haven't filled the gender value and the value is changed to the default value. i've checked it with screenshots.</p>
  
  <p>submit is here on the page:</p>
  
  <pre><code>&lt;div class="col-xs-18"&gt;
     &lt;input id="CredentialsAction" class="btn btn-primary btn-block" type="submit" value="Klick" title="Klick"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>i click it like that: </p>
  
  <pre><code>casper.then(function(){
      this.click('input[title*="Klick"]');
  });
  </code></pre>
  
  <p>i also tried to choose gender like that: </p>
  
  <pre><code>casper.then(function (){
      this.sendKeys('select#Gender', 'w');
  });
  </code></pre>
  
  <p>this is also working in the first moment, gender is choosen till i klick the submit button. any ideas what im doing wrong? or any ideas on wich other ways i could select the form? </p>