title: "formatter doesn't support the nested 'param' element" error with PMD Ant task
body: <p>I'm using Ant 1.9.4.</p>
  
  <p>When I run the following target:</p>
  
  <pre><code>&lt;presetdef name="pmd.scan"&gt;
      &lt;pmd rulesetfiles="${root.dir}/scripts/pmd5_rules.xml" minimumPriority="${pmd.minimum.priority}"&gt;
          &lt;formatter type="xml" toFile="${pmd.report.xml}" showSuppressed="true"&gt;
              &lt;param name="linePrefix" value=".line"/&gt;
          &lt;/formatter&gt;
          &lt;fileset refid="pmd.files"/&gt;
          &lt;sourceLanguage name="java" version="1.8"/&gt;
      &lt;/pmd&gt;
  &lt;/presetdef&gt;
  </code></pre>
  
  <p>I end up with <strong>formatter doesn't support the nested "param" element.</strong> How to resolve this?</p>