Revision 1774473

On the ocsp-verification branch: Implement request constructor,
export, import and acccessors.

* serf_bucket_types.h
  (serf_ssl_ocsp_response_parse): Fix return type.

* buckets/ssl_buckets.c
  (free_ocsp_request): New; pool cleanup function.
  (serf_ssl_ocsp_request_t, serf_ssl_ocsp_response_t): Define types.
  (serf_ssl_ocsp_request_create,
   serf_ssl_ocsp_request_body,
   serf_ssl_ocsp_request_body_size,
   serf_ssl_ocsp_request_export,
   serf_ssl_ocsp_request_import): Implement these functions.
  (serf_ssl_ocsp_response_parse,
   serf_ssl_ocsp_response_verify): Add fake implementations.