Closes #154.

Fixes https://gitlab.labs.nic.cz/knot/knot-resolver/issues/154
I'm sorry I broke the module in 06b0d3d4.  Thaks Vita!

... to allow NEWS update

The epoch indices are from [1..period].

i.e. downgrade a zone to insecure when *all* DNSKEYs of the apex are
unverifiable due to unimplemented DNSKEY or DS algorithms.
Fixes https://gitlab.labs.nic.cz/knot/resolver/issues/210

Closes #204.

... to fix conflict in NEWS.

Which semantically reverses part of fbe88ccd.
I would personally prefer not to, but I guess it would be less consistent.
Also make the error messages a little better.

Almost all of them were getting redirected correctly, but why keep the
old ones.  Also update a couple nitpicks directly around.

I broke this in 3da1535e when changing stuff around addr2reverse;
now it should be OK, after partially reversing that commit.
I'm sorry.  Thanks to Vita for noticing the breakage.

At least it seems so...

Fixes https://gitlab.labs.nic.cz/knot/resolver/issues/204

(so that NEWS can get updated)

In reverse (PTR) records, now the last definition wins,
and non-canonical names don't get (shadowed) records.

 * changed stype to type
 * fix enquening queries from predict log
 * keep heuristic in function generate to predict upcoming epoch

... data from cache as keys for validation

... data from cache as keys for validation

Issue #127.

Answer is mangled first and then copied to cache.

Noticed after removal of its lua binding in commit 3be76db7.

Clearing the query flags lead to kresd iterating over authoritative
servers.  Related: https://gitlab.labs.nic.cz/knot/resolver/issues/217

Note that validation of synthesised AAAA behind a CNAME doesn't work
when policy.FORWARD + dns64.  Example: www.regiojet.cz.
policy.STUB + dns64 seems not to work at all.

If CNAME chain occurs CNAME is placed before AAAA.

Maybe some coverity issues will get fixed, even though
they had seemed not to be affecting our use cases in kresd.

Tests+Deckard look OK and I've been using my system and kresd with
system-wide 0.9.21 for some time already.

Closes #125 and #208.