title: atk4 grid lookup dropdown values
body: <p>i've got a last question, is it possible to make a grid value lookup, examples:</p>
  
  <p>db values =1 -> label = label1 (dropdown values), how i can define table element to make 
  automatic lookup?</p>
  
  <pre><code> $this-&gt;addField('tipo_mat');
  </code></pre>
  
  <p>Array lookup -> array(1->'Label1',2->'Label2');</p>
  
  <p>thank's</p>