title: Required error messages based on label in html?
body: <p>I try to i18n a WicketApplication that uses forms, and labels. </p>
  
  <p>I use Wicket 7.3.0, running from the maven-quickstart in jetty.</p>
  
  <p>I would like the Feedback message to use the <code>label</code> contents, but now it uses the field-name. I remember seeing this working sometime in the past, but it seems not to work now. Maybe I relied on an edge-case. Anyway, my question is if this is the 'proper' way, or if not, what I should do differently.</p>
  
  <p>This is my (test-case) code:</p>
  
  <h2>HTML</h2>
  
  <pre><code>&lt;body&gt;
      &lt;div wicket:id="fp"&gt;&lt;/div&gt;
      &lt;form wicket:id="f"&gt;
          &lt;table&gt;
          &lt;tr&gt;&lt;td&gt;&lt;label wicket:for="naam"&gt;&lt;wicket:message key="Naam"&gt;&lt;/wicket:message&gt;&lt;/label&gt;&lt;/td&gt;&lt;td&gt;&lt;input wicket:id="naam" /&gt;&lt;/td&gt;&lt;/tr&gt;
          &lt;tr&gt;&lt;td&gt;&lt;label wicket:for="adres"&gt;&lt;wicket:message key="Adres"&gt;&lt;/wicket:message&gt;&lt;/label&gt;&lt;/td&gt;&lt;td&gt;&lt;input wicket:id="adres" /&gt;&lt;/td&gt;&lt;/tr&gt;
          &lt;tr&gt;&lt;td&gt;&lt;label wicket:for="woonplaats"&gt;&lt;wicket:message key="Woonplaats"&gt;&lt;/wicket:message&gt;&lt;/label&gt;&lt;/td&gt;&lt;td&gt;&lt;input wicket:id="woonplaats"/&gt;&lt;/td&gt;&lt;/tr&gt;
          &lt;/table&gt;
          &lt;a wicket:id="save"&gt;Save!&lt;/a&gt;
      &lt;/form&gt;
  &lt;/body&gt;
  </code></pre>
  
  <h2>Java</h2>
  
  <pre><code>public HomePage(final PageParameters parameters) {
          super(parameters);
          final FeedbackPanel fp = new FeedbackPanel("fp");
          fp.setOutputMarkupId(true);
          this.add(fp);
          Form f = new Form&lt;Void&gt;("f") {
          };
          f.setOutputMarkupId(true);
          f.add(new TextField("naam", Model.of("Rob")).setRequired(true));
          f.add(new TextField("adres", Model.of("Fantasieweg 4")));
          f.add(new TextField("woonplaats", Model.of("Babbelerdam")).setRequired(true));
          // TODO Add your page's components here
          f.add(new AjaxSubmitLink("save", f) {
              @Override
              protected void onAfterSubmit(AjaxRequestTarget target, Form&lt;?&gt; form) {
                  target.add(fp);
              }
  
              @Override
              protected void onError(AjaxRequestTarget target, Form&lt;?&gt; form) {
                  // TODO Auto-generated method stub
                  target.add(fp);
              }
          });
          this.add(f);
      }
  </code></pre>
  
  <h2>WicketApplication.properties</h2>
  
  <pre><code>Required=Veld ${label} is verplicht
  Naam=PropertyNaam
  Adres=PropertyAdres
  Woonplaats=PropertyWoonplaats
  </code></pre>