Fixing #484

See merge request !610

knot_pkt_begin: fix beginning the same section again

The .pos value might get wrong (though I see no usage ATM).

Notes:
- It still returns KNOT_EOK in case of equality; that's due to usage
  in resolver and requirement to special-case KNOT_ANSWER anyway.
- I would personally assert(false) on all internal failures (e.g. EINVAL),
  as immediate abortion seems preferrable when in debug mode, but the
  code around typically doesn't do that, so I left it without assertions.

See merge request !609

The .pos value might get wrong (though I see no usage ATM).

Notes:
- It still returns KNOT_EOK in case of equality; that's due to usage
  in resolver and requirement to special-case KNOT_ANSWER anyway.
- I would personally assert(false) on all internal failures (e.g. EINVAL),
  as immediate abortion seems preferrable when in debug mode, but the
  code around typically doesn't do that, so I left it without assertions.

Fixing https://gitlab.labs.nic.cz/labs/knot/issues/486

See merge request !608

Spelling, grammar, and typo cleanup

See merge request !606

doc: add warning about timers infuencing zsk key lifetime

closes issue #481

See merge request !603

zonedb: fix typo

http://boostrap.com/ ;-)

Waiting for https://gitlab.labs.nic.cz/labs/knot/merge_requests/587

See merge request !598

Don't preserve CD flag

See merge request !602

internet: skip empty non-terminal parents during delegation lookup

See merge request !600

http://boostrap.com/ ;-)

QP coverity

See merge request !596

I think the reported "issues" couldn't really happen,
but it seems better to refactor to get rid of them.