title: ATK4 Autocomplete issue
body: <p>I'm new to ATK4.
  I'm trying to implement an Autocomplete field, but I had only an error when I try to define the field.
  I'm running all on a MAC with the last version (4.2.4) of ATK4. All other functions (field types) seems to work well, but when I define a field of type autocomplete I get the same error I saw on the example: <a href="http://codepad.agiletoolkit.org/autocomplete" rel="nofollow">http://codepad.agiletoolkit.org/autocomplete</a></p>
  
  <p>The case is I defined a model:</p>
  
  <pre><code>class Model_Agenda extends Model_Table {
      public $entity_code='Agenda';
      function init(){
          parent::init();
  
          $this-&gt;addField('DATE');
          $this-&gt;addField('TIME');
          $this-&gt;addField('DRIVERID');
          $this-&gt;addField('STUDENTID');
          $this-&gt;hasOne('STUDENTID')-&gt;display(array('form'=&gt;'autocomplete/Basic'));
  
      }
  }
  </code></pre>
  
  <p>and then on my Page:</p>
  
  <pre><code>    $form = $this-&gt;add('Form');
      $form-&gt;addField('ReadOnly','Date')-&gt;Set($_GET['date']);
      $form-&gt;addField('ReadOnly','Time')-&gt;Set($_GET['time']);
      $form-&gt;addField('ReadOnly','Driver')-&gt;Set($_GET['driverid']);       
      $client=$form-&gt;addField('autocomplete','studentid');
  </code></pre>
  
  <p>something simple, but nothing, I cannot get the autocomplete field, I ever get an error that say that "autocomplete.php" doesn't exist (actually the file doesn't exist and I try to download the github module, but either that module includes this file), anyway the error I get is:</p>
  
  <p>Exception_PathFinder, code: 0</p>
  
  <p>Additional information:</p>
  
  <pre><code>file: Form/Field/Autocomplete.php
  type: php
  attempted_locations:
  0: /Library/WebServer/Documents/rutas/lib/Form/Field/Autocomplete.php
  1: /Library/WebServer/Documents/rutas/atk4/lib/Form/Field/Autocomplete.php
  2: /Library/WebServer/Documents/rutas/atk4-addons/mvc/Form/Field/Autocomplete.php
  3: /Library/WebServer/Documents/rutas/atk4-addons/misc/lib/Form/Field/Autocomplete.php
  class: Form_Field_Autocomplete
  namespace:
  orig_class: Form_Field_Autocomplete
  /Library/WebServer/Documents/rutas/atk4/lib/PathFinder.php:207
  </code></pre>
  
  <p>Someone could help me please?</p>