title: XWPFRun.setText() doesn't seem to respect line breaks or tabs?
body: <p>Here is the sample code, the "\t" not work for this setText method?:</p>
  
  <pre><code>XWPFDocument document = new XWPFDocument();
  XWPFParagraph tp = document.createParagraph();
  XWPFRun tRun = tp.createRun();
  tRun.setText("a");
  tRun.setText("\t"); // not work
  tRun.setText("b");
  
  FileOutputStream outStream = null;
  try {
      outStream = new FileOutputStream("testTabWithPOI.doc");
      document.write(outStream);
      outStream.close();
  } catch (FileNotFoundException e) {
      e.printStackTrace();
  } catch (IOException e) {
      e.printStackTrace();
  }
  </code></pre>