title: Wicket page is refreshed if use ajax after form is submitted with target=_blank
body: <p>I have a preview button. When user press preview, form is submitted on new tab to show a pdf file have data in form.
  I use a custom SubmitLink to do that
  <strong>SubmitResourceLink</strong></p>
  
  <pre><code>public abstract class SubmitResourceLink extends SubmitLink implements IResourceListener {
  private final IResource resource;
  
  @Override
  public final void onResourceRequested() {
      Attributes a = new Attributes(RequestCycle.get().getRequest(), RequestCycle.get().getResponse(), null);
      resource.respond(a);
  }
  </code></pre>
  
  <p>Implement on form</p>
  
  <pre><code>new SubmitResourceLink("previewBtn", form, new JasperReportsResource() {
          private static final long serialVersionUID = -2596569027102924489L;
  
          @Override
          public byte[] getData(Attributes attributes) {
              return control.getExportPreviewByteStream(estimateModel.getObject());
          }
      }) {
          private static final long serialVersionUID = 1L;
  
          @Override
          protected String getTriggerJavaScript() {
              String js = super.getTriggerJavaScript();
              js = "document.getElementById('" + form.getMarkupId() + "').target='_blank';" + js;
              return js;
          }
  
          @Override
          public void onSubmit() {
              form.add(AttributeModifier.append("target", Model.of("_blank")));
              processInputs(form);
              onResourceRequested();
          }
      }.setDefaultFormProcessing(false);
  </code></pre>
  
  <p>When I press preview, a new tab is opend. But when I input in any ajax component (ex:AutoCompleteTextField), ajax reponse data xml: <code>&lt;ajax-response&gt;&lt;redirect&gt;....&lt;/redirect&gt;&lt;/ajax-response&gt;</code> and refresh page.
  Now, I want after press preview, I still use current form normaly.
  Thank.</p>