RT1941: c_rehash.pod is missing

Add the file written by James Westby, graciously contributed
under the terms of the OpenSSL license.

Reviewed-by: Andy Polyakov <appro@openssl.org>
RT2379: Additional typo fix

Andy found an additional typo "can be can be".
Now I have that silly "Que sera sera" song stuck in my head.

Reviewed-by: Andy Polyakov <appro@openssl.org>