When there is no time in a key file, dnssec-settime will print
"UNSET", but to unset a time the user must specify "none" or "never".
This change allows "unset" or "UNSET" as well as "none" or "never".
The "UNSET" output remains the same to avoid compatibility problems
with wrapper scripts.
I have also re-synchronized the "Timing Options" sections of the man pages.
Closes #3361 (closed)