title: JRXmlDataSource with queryString give no records
body: <p>I have a problem with XML datasource for Jasper Reports. When i use <code>selectExpression</code> in <code>JRXmlDataSource</code> constructor, everything works, but when i use <code>queryString</code> in <code>.jrxml</code>, i get no records.</p>
  
  <p>working example:</p>
  
  <pre><code>JRXmlDataSource ds2 = new JRXmlDataSource(new FileInputStream(dataSourceFile), "/pages/page");
  </code></pre>
  
  <p>not working example:</p>
  
  <pre><code>JRXmlDataSource ds1 = new JRXmlDataSource(new FileInputStream(dataSourceFile));
  
  &lt;jasperReport&gt;
      &lt;queryString language="xPath"&gt;
          &lt;![CDATA[/pages/page]]&gt;
      &lt;/queryString&gt;
      ...
  &lt;/jasperReport&gt;
  </code></pre>
  
  <p>Data XML:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;pages&gt;
      &lt;page&gt;
          &lt;firstname&gt;X&lt;/firstname&gt;
          &lt;lastname&gt;Y&lt;/lastname&gt;
      &lt;/page&gt;
      &lt;page&gt;
          &lt;firstname&gt;Z&lt;/firstname&gt;
          &lt;lastname&gt;V&lt;/lastname&gt;
      &lt;/page&gt;
      &lt;page&gt;
          &lt;firstname&gt;B&lt;/firstname&gt;
          &lt;lastname&gt;S&lt;/lastname&gt;
      &lt;/page&gt;
  &lt;/pages&gt;
  </code></pre>