Prepare NEWS for distcheck
DDNS/DNSSEC: Leak fix, small fixes.

 - Do not copy SOA with RRSIG, it will be dropped anyway.
 - Small code improvements, assertion added.

Refs #4
DNSSEC: backend library cleanup function, register using atexit()

Fixes some still-reachable memory leaks. The function should be
called upon termination by all tools dealing with crypto (currently
knotd, knsec3hash, and knsupdate).

refs #4
DNSSEC: fix keytag calculation for in-zone keys

(Also fixes invalid read reported by Valgrind.)

refs #4
Double free fix.
Sort arriving RRSets.

 - Needed for valid DDNS signing
 - Might be needlesly slower for AXFR (no real-life impact though IMO)
DDNS: Skip DNSSEC records when deleting 'all' record from apex.
Leak fix.
doc: fix log syntax

closes #185
Do not create DNSSEC changesets when DNSSEC is disabled.

- This lead to a leak
zone-load: improve error messages

close #184
zone-load: fix access check