Refs #1502

- Added some simple API functions to RDATA and RRSet.

fixes #1491 @15m

- Assertion was not making sense for rr types with non-fixed length.

fixes #1492

Refs #1480 @1.5h

- Removed fprintf from rrset.c
- Added rrset debug messages to debug.h
Refs #1460

refs #1460

refs #1460

refs #1460

- Was only doing it for AXFR, now for both.
- Was not adding the last incoming packet.

refs #1460

- Missing previous digest length in the data to sign.
  (again...)

refs #1460

Conflicts:
	Knot.files

- Allocating buffer for packets in XFR/OUT.
- Saving packets to the buffer.
- Fixed reservation of space for TSIG RR.
- Changed tsig_sign_next() API to take the buffer with packets.

refs #1460

- Missing previous digest length.
- Wrong original ID.
- Wrongly copied digest.

refs #1460

refs #1460

- If there is a TSIG key associated with the zone and remote
  and the client does not sign the query, return REFUSED.

refs #1460

- Fixed saving TSIG error in xfr_check_tsig().
  TODO: needs refactoring.
- Fixed adding TSIG with error code
  - copying TSIG from query.

refs #1460

Refs #1480 @0.1h

Refs #1480 @0.1h

Refs #1460 @0.75h

Fixes #1481 @0.5h

Fixes #1482

Refs #1480 @2h

refs #1480 @3.5h

refs #1480