mod_rest: Roundtrip disco and items when string or boolean is used E.g. {disco:true} turns to <query/> and back to {disco:true}, same with {items:true}. Similarily, {disco:"node"}, {items:"node"} turn into <query node="node"/> and back.

<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>