title: customize error message for required field with <aui:select > in liferay
body: <p>I'm trying to validate a required Select option with aui.</p>
  
  <p>for input fields the code below works without any issue :</p>
  
  <pre><code>&lt;aui:input name="name" value="${name}" label="name"&gt;
       &lt;aui:validator name="required" errorMessage="your-message-here"&gt;&lt;/aui:validator&gt;
  &lt;/aui:input&gt;
  </code></pre>
  
  <p>But with Select option field, I cannot customise the required error message :</p>
  
  <p>for example :</p>
  
  <pre><code>&lt;aui:select required="true" label="field.label" id="id" name="name" useNamespace="false"&gt;
      &lt;aui:option value="" label="first.option" selected="option1"/&gt;
      &lt;aui:option value="" label="second.option" selected="option2"/&gt;
      &lt;aui:option value="" label="third.option" selected="option3"/&gt;
  
  &lt;/aui:select&gt;
  </code></pre>
  
  <p>My Question is : How can I customize the error message for required field in <code>&lt;aui:Select&gt;</code></p>
  
  <p>Thanks .</p>