Conflicts:
	src/knot/server/tcp-handler.c

(just for testing, will be refactored)

IXFR SOA response implemented.

Fixed packet maxsize calculation.
Support for unlimited (only to 64k) packets for TCP.
Fixed optional authority section.

See RFC6672, 3.1 CNAME Synthesis

No additional for referral response.

No DNAME, CNAME, DNSKEY, NSEC/NSEC3.

* Answers CH zone and error messages.

States:
* MORE -> FAIL|FULL (reads query, fails to parse or makes answer)
* FAIL -> FULL (generates error response)
* FULL -> FAIL|FINISH (writes answer, fails or succeeds)
* FINISH -> MORE (resets context for new query)