Issue #2097261 by dafeder, Ludo.R, stefan.r, Nixou, Dave Reid, Leksat,...

          if (isset($item['description'])) {

            $file->description = $item['description'];

          }

          $text = $settings['text'];

          if (module_exists('i18n_string')) {

            $key = 'file_entity:file_download_link:' . $entity_type . ':' . $instance['bundle'] . ':link_text:' . $text;

            $text = i18n_string($key, $text);

          }

          $element[$delta] = array(

            '#theme' => 'file_entity_download_link',

            '#file' => $file,

            '#text' => $settings['text'],

            '#text' => $text,

          );

        }

      }

<?php

/**

 * Implements hook_i18n_string_info().

 */

function file_entity_i18n_string_info() {

  $groups['file_entity'] = array(

    'title' => t('File Entity'),

    'format' => FALSE,

  );

  return $groups;

}

/**

 * Implements hook_i18n_string_list().

 */

function file_entity_i18n_string_list($group) {

  if ($group == 'file_entity') {

    $fields = field_info_instances();

    $strings = array();

    foreach ($fields as $entity_type => $bundles) {

      foreach ($bundles as $bundle => $fields) {

        foreach ($fields as $field_key => $field_settings) {

          foreach ($field_settings['display'] as $view_mode => $view_mode_settings) {

            if (!empty($view_mode_settings['type']) && $view_mode_settings['type'] == 'file_download_link') {

              $text = $view_mode_settings['settings']['text'];

              $key = $entity_type . ':' . $bundle . ':' . 'link_text';

              $strings['file_entity']['file_download_link'][$key][$text] = $text;

            }

          }

        }

      }

    }

    return $strings;

  }

}