refs #1995

Some newer versions of libc exported recvmmsg() symbol,
so it was detected even if the kernel couldn't support it.

refs #1995 @1h30m

- Turned assert in zone-load to if-block.
- Added more debug messages to zone-load.
- Added NULL check to knot_rdata_deep_free (possible NULL dereference - rdata->items).

Refs #1877

Refs #1877

Refs #1877

- Moved to separate subsections.

No \code{}.

refs #1877 @5m

refs #1877 @15m

refs #1877

- Replaced by @pxref where applicable

Refs #2002

- IPSECKEY rdata were being parsed in wrong way - two items were stored in one. This caused no problems during responding.
- Changed storing of APL rdata so that it is the same as TXT, currently, it might have caused undesired behaviour with transfered rdata or with rdata loaded from binary.

Closes #2002 @3h

Updated log messages for denied outgoing transfers.

fixes #2007 @3h

refs #1877

refs #1877

refs #1877

- Introduction fixed
- Requirements fixed
- Installation fixed partially

Refs #1997

- Reorganized groups.
- Updated main page.

refs #1996 @30m

- If node was empty no action was taken, but all RRs from node in the other tree
  have to be added to ADD section of changeset in such a case.
- Renamed and moved functions for clarity.