man pages for configuration xml files

It would also be nice to have man pages for the config files, even though
"man kasp.xml" is a little awkward, perhaps migrate that to kasp.conf in
a future major release?

Specific about the SOA TTL:

Perhaps a comment in the stock config file stating
something along these lines would be good, eg:

<!-- Specify the TTL value used in the unsigned zone. This is used by
ods-enforcerd, which does not read zone content, to calculate various
key rollover safety timings
->