- Remove the ValidateCertificateResponse::ErrorItem::certId member. The

- Remove the ValidateCertificateResponse::ErrorItem::certId member. The
  user should always link with a certificate, not with an index to certificate.
- The CertValidateMessage::parseResponse takes as argument the list of peer
  Certificates. It uses this list to fill the ValidateCertificateResponse
  object.
- Return ERR_GATEWAY_FAILURE/HTTP_INTERNAL_SERVER_ERROR error if:
   * Failed to compose the  Ssl::CertValidateMessage message to sent to
     cert validator
   * The response from cert validator is wrong
   * The cert validator returns an error.