Fix soft dependency

Fixes #9

That unrelated module, whoever runs that thing… can now move from a blatant hack, to something really complicated and completely un-The Drupal Way :tm:
```php
/**
 * Implements hook_queues_views_handler_field_queue_operations_alter().
 */
function pub_editorial_queues_views_handler_field_queue_operations_alter ($links) {
  // Include the dropbutton css from pub_editorial.
  drupal_add_css(drupal_get_path('module', 'pub_editorial') . '/css/pub_editorial.css', array('weight' => 10));
}
```