supported dns_name_cksum().
some more comments.
support rdata_cksum, added more tests
some documentation
use network byte order for name checksum
supported checksumming in rdataslab_fromrdataset.
checksum support for rdataslab merge.  also specialize ns_rdata for non-case sum
supported checksum for rdataslab_subtract.
preliminary part of dns_db_cksum().
calculate checksums on load.
introduce dns_rdataslab_cksum as it's a bit more efficient.
update checksums on addrdataset.
update checksum for simple subtract case.
a bit of refactoring.
adjust checksums in case of removing an entire RRset.
comment wording fix.
extended log on load zone to dump zone checksums
logged checksums after xfr-in.
supported rndc status zone to show zone's serial and checksums.
fixed off by one error in checksum adjustment.