Divided into two parts. In first part the 'prev' pointers are
set. The second does the rest of the work. It's necessary because
the 'prev' pointers are used in search for domain names in RDATA
and may not be yet set well. This caused some rare problems.

refs #1952 @4h

- Logging section completed
- Added examples for remotes and zones
- typo fixes
- needs review

Refs #1997

refs #1877

refs #1877

refs #1877

Formatting and typo.

refs #1877

refs #1877

refs #1877

refs #1877

- Updated introduction.
- Removed 'Security Considerations' chapter and Appendix B.
- Updated authors.
- Fixed case in section names.

refs #1877 @1h

refs #1877

refs #1877

refs #1877

refs #1877

refs #1877

This reverts commit 243d4ac1.

This reverts commit 756debd0.

Added some missing read locks.
TODO: may deadlock somewhere, some functions still find zone from zonedb
and may corrupt new reloaded zone instead of zone the transfer was started

refs #1976

refs #1976

- Actual RDATA of zone were beeing changed due to improper API usage.

Refs #1965

- Missing NSEC/NSEC3 is no longer considered an error.

refs #1970

refs #1950

- If a node contains a CNAME RRSet or just a RRSIG covering a
  CNAME, the server will not try to resolve the CNAE chain.

refs #1971

This option allows binding to the same port using separate
IPv6 and IPv4 socket.

refs #1877

refs #1877

- Freeing RRSIGs after RRSet deep copy (there's no switch that would mean no RRSIGs copyiing)
- Added assert to zone-dump that checks for such state

Refs #1752