title: Yii2 Asset Bundle: How to set headers?
body: <p>I am using Asset Bundles of yii2. But I do not find a away to influence the http header of each file (css and js). For example I want to set the cache.
  For the controllers I do this: </p>
  
  <pre><code>'class' =&gt; 'yii\filters\HttpCache', 
              'only' =&gt; ['index', 'view'],
              'cacheControlHeader' =&gt; 'public, max-age=3600',
              'lastModified' =&gt; function ($action, $params) {
                  $q = new \yii\db\Query();
                  return $q-&gt;from('user')-&gt;max('updated_at');
              },
  </code></pre>
  
  <p>But how to do this for the Assets / Asset Bundles?</p>