mod_storage_xmlarchive: Insert micropauses in long-running queries Allows other processing to be interleaved with long-running queries. Drops 0.9 support since it requires util.async, but 0.9 really should be EOL by now.

<tr>
  <th>What is {x} {op} {y}?</th><td>
    <input name="captcha_challenge" type="hidden" value="{challenge}">
    <input name="captcha_reply" pattern="[0-9]+" required type="number">
  </td></tr>