[translations] autolocale automatic installation

[Jakub Suchy]

Gabor Hojtsy wrote:
> 1. Check the database (or the module_list()) in the early callback.
> 2. Check it again at the callback called last.
> 3. Compute the difference.
> 4. Import what needs to be imported

Is this clean and does it have some catch? It works for me

function autolocale_form_alter($form_id, &$form) {
  // Process only if module form is displayed
  if ($form_id === "system_modules") {

    // Determine which modules are enabled at the moment
    if (is_array($form['status']['#default_value'])) {
      $autolocale_modules = array();
      foreach ($form['status']['#default_value'] as $module) {
        array_push($autolocale_modules, $module);
      }

      // We MUST skip module confirm form
      if ($_GET['q'] != "admin/build/modules/list/confirm") {
        $enabled = array_diff($autolocale_modules, $_SESSION['autolocale_modules']);
        if (!empty($enabled)) {
          // These modules have been enabled
          print_r($enabled); // TODO
        }
      }

      // Store modules for next reload
      $_SESSION['autolocale_modules'] = $autolocale_modules;
    }

  }
}