I intentionally didn't mark the function names as code or similar,
as changing formatting every other word seemed too visually distracting.

It's never been used apparently, since its introduction in 5b288464.
This commit doesn't depend on knot being 2.7 at all.

As Marek noted, the option is meant to fix bad stub-resolvers,
and those may not put good randomness into the ID.

... thanks to new API in libknot-2.7.
Apart from being simpler, it now rotates even uncached answers.

This second part of API replacement in particular lengthens the code,
but I hope the new expression will be easier to understand at least.

When at it, switch to generating the libzscanner bindings.

This error code has been unused in knot since 2.3, and now it got removed.

The _t isn't uint8_t* anymore but a structure with .len and .data.

libknot 2.7 stopped doing tolower inside its functions.
We're mostly OK, as packet parsing does DNSSEC canonization
(which lower-cases most things), but there are stil some places
that needed care, e.g. NSEC's next name.

To work on RRSIG TTLs, libknot >= 2.7.1 is needed.

It's not optimal; we can improve performance later.

- <dnssec/**> -> <libdnssec/**>
- <zscanner/**> -> <libzscanner/**>

nitpicks

See merge request !649

packaging - use upstream files

See merge request !648