title: Trying to use gettext without country code ('es' instead 'es_ES')
body: <p>I have the next files in my php project:</p>
  
  <pre><code>libraries/locale/es_ES/LC_MESSAGES/messages.po
  libraries/locale/es_ES/LC_MESSAGES/messages.mo
  libraries/locale/es/LC_MESSAGES/messages.po
  libraries/locale/es/LC_MESSAGES/messages.mo
  </code></pre>
  
  <p>Both are the same file edited with PoEdit just differenced by Catalog->Properties->Language (es and es_ES respectively) </p>
  
  <p>And this code into localization.php file</p>
  
  <pre><code>$language = "es_ES.UTF-8";
  putenv("LANG=$language");
  setlocale(LC_ALL, $language);
  bindtextdomain(STRING_DOMAIN, LOCALE_PATH);
  textdomain(STRING_DOMAIN);
  
  echo "Test translation: "._('string to translate');
  </code></pre>
  
  <p>This code works fine and 'string to translate' is displayed correctly. However if I try to use the generic 'es' code:</p>
  
  <pre><code>$language = "es.UTF-8";
  </code></pre>
  
  <p>...String is not translated. Seems to be related to locales installed in my ubuntu (es_ES.utf8 exists but not es.utf8) </p>
  
  <p>Can I force gettext to use es.UTF-8 file? </p>