title: charset utf-8 not working on Export as excel seet
body: <p>i am try to export excel sheet in in php. all is fine but German character is not working</p>
  
  <p>my header is like :</p>
  
  <pre><code>header("Pragma: public");
  header("Expires: 0");
  header("Content-Type:application/vnd.ms-excel; charset=utf-8");
  header("Content-type:application/x-msexcel; charset=utf-8");
  header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
  header("Content-Type: application/force-download");
  header("Content-Type: application/octet-stream");
  header("Content-Type: application/download");
  header("Content-Disposition: attachment;filename=report.xls");
  header("Content-Transfer-Encoding: binary ");
  </code></pre>
  
  <p>in html live page it shows German character n utf8 like <code>ßäöü</code> but when i export as excel then in excel sheet it is like <code>ÃŸÃ¤Ã¶Ã¼</code> why ?</p>