Update to Drupal 8.0-dev-2015-11-17. Commits through da81cd220, Tue Nov 17 15:53:49 2015 +0000, Issue #2617224 by Wim Leers: Move around/fix some documentation.

core/lib/Drupal/Core/StringTranslation/TranslationManager.php

@@ -134,6 +134,11 @@ class TranslationManager implements TranslationInterface, TranslatorInterface {
    *   The translated string.
    */
   protected function doTranslate($string, array $options = array()) {
+    // If a NULL langcode has been provided, unset it.
+    if (!isset($options['langcode']) && array_key_exists('langcode', $options)) {
+      unset($options['langcode']);
+    }
+
     // Merge in options defaults.
     $options = $options + [
       'langcode' => $this->defaultLangcode,