doc fixes, title change

Would not be translatable... Is bad, m'kay?

Could be overridden in subclasses like:
```php
class asdf extends ZipBatchImporter {
  public static function getForm(array &$form_state) {
    $form = parent::getForm($form_state);
    $form['fs']['#title'] = t('My Different Title');
    return $form;
  }
  [...]
}