OCSP Updates
1. Add option to example server and client to check the OCSP responder.
2. Add option to example server and client to override the URL to use
   when checking the OCSP responder.
3. Copy the certificate serial number correctly into OCSP request.
   Add leading zero only if MS bit is set.
4. Fix responder address used when Auth Info extension is present.
5. Update EmbedOcspLookup callback to better handle the HTTP
   response and obtain the complete OCSP response.