title: CakePHP 2.0 AuthComponent use own column name
body: <p>how i can use following. 
  i have columns in my table wf_users: <code>wf_username, wf_password</code> now in my form i don´t wanna anyone to se my table structure therefore i use in my Form</p>
  
  <p><code>$this-&gt;Form-&gt;input("username")­;</code><br>and not the <br><code>$this-&gt;Form-&gt;input("wf_username")­;</code><br>
   my post looks like this </p>
  
  <p><code>User=&gt;array( 'username', 'password' );</code> </p>
  
  <p>now i need them to change into my named column or that want do the trick to login in the allowed area because it try´s to fetch with wrong column (with <code>"username"</code> not with <code>"wf_usernam"</code>).</p>
  
  <p>My AppController:</p>
  
  <pre><code>class AppController extends Controller {
  
      public $viewClass = 'Theme';
  
      public $theme;
  
      public $components = array(
                              'Auth'=&gt; array(
                                  'loginRedirect'=&gt;array('controller'=&gt;'users', 'action'=&gt;'dashboard'),
                                  'logoutRedirect'=&gt;array('controller'=&gt;'users', 'action'=&gt;'dashboard'),
                                  'authError'=&gt;'yout can´t access the page!',
                                  'authorise'=&gt;array('Controller'),
                                  #'authenticate' =&gt; array(
                                  #   'Form' =&gt; array(
                                  #       'fields' =&gt; array(
                                  #           'wf_auth_user_username' =&gt; 'username',
                                  #           'wf_auth_user_password' =&gt; 'password'
                                  #       )
                                  #   )
                                  #)
                              ),
                              'Session'
                           );
  
      //Before mainlayout
      public function beforeFilter() {
          parent::beforeFilter();
          $this-&gt;theme = 'SM';
          $this-&gt;Auth-&gt;fields = array('username'=&gt;'wf_auth_user_username','password'=&gt;'wf_auth_user_password');
          //Configure AuthComponent
          $this-&gt;Auth-&gt;allow('*');
          //Logged in user
          $this-&gt;set('isauth', 'loggedout'); //$this-&gt;userpanelAuth());
      }
  
      public function isAuthorized($user) {
          return true;
      }
  
      protected function userpanelAuth() {
          if($this-&gt;isAuthorized()) {
              return 'loggedin';  
          }else{
              return 'loggedout';
          }
      }
  
  }
  </code></pre>
  
  <p>And This is my Form:</p>
  
  <pre><code>                            &lt;div id="display-panel"&gt;
                                  &lt;?
  echo $this-&gt;Session-&gt;flash();
  
                                          echo $this-&gt;Form-&gt;create('User', array('action' =&gt; 'login'));
                                          echo $this-&gt;Form-&gt;input(
                                              'username', 
                                                  array('label'=&gt;false, 'div'=&gt;false,'placeholder'=&gt;'Benutzername',''));
                                          echo $this-&gt;Form-&gt;input(
                                              'password', 
                                                  array('label'=&gt;false, 'div'=&gt;false,'placeholder'=&gt;'Passwort'));
  
                                          echo $this-&gt;Form-&gt;end(array('label'=&gt;'login','div'=&gt;false));
                                  ?&gt;
                              &lt;/div&gt;
  </code></pre>