[PATCH] gnu: Add whois.

[ng0]

For "historic" reasons this also bundles mkpasswd to encrypt passwords.
I don't want to unbundle this right now, this should be a job for upstream.

PPoint is: A whois client for guix. We have no whois right now. Well that is if
you see the very limited one of bind as a client, then we do have one.

whois hackint.eu worked (the bind one just tells you "i don't know .eu what is 
.eu ..."),
so I assume it is functional.