title: Laravel 4 alpha_dash validation odd issue
body: <p>Laravel 4, validation. The following passes validation even though the username input field contains invalid characters of "đšđšžšđčč". Why is that? Should not alpha_dash allow only '/^([a-z0-9_-])+$/i'?</p>
  
  <pre><code>public function postSignup()
  {
      $data = Input::all();
  
      $validator = Validator::make(
          $data,
          array('username' =&gt; 'required|alpha_dash')
      );
  
      if ($validator-&gt;fails())
      {
          echo 'fail';
      }
      else
      {
          echo 'ok';
      }
  
      return;
  }
  </code></pre>