mod_http_oauth2: Reflect changes to defaults etc - Resource owner password grant was disabled by default - Tokens now include a hash of client_id making it possible to be reasonable sure that they were issued to a particular client

<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>