Conflicts:
	src/libknot/updates/ddns.c

Problem was the function is copied from another one which
always decrements the arcount and trims the TSIG RR. But with
aggregated responses, this should be stripped not from first,
but from the packet actually containing the TSIG.

refs #122

refs #118

refs #118

Either set it to 0 or comment out the statement.

Main changes:
* 'system.hostname' config option is deprecated
* 'system.identity' is used for 'id.server' and 'hostname.bind'
* 'system.version' is used for 'version.server' and 'version.bind'
* In addition, config options (and NSID) support boolean on|off
* When on, the automatic default is filled on config load:
  * FQDN hostname (or at least hostname) for NSID and system.identity
  * Version string for system.version

The config options are still turned off by default.
refs #113

There was also a small error when a TCP master socket was removed,
the next one was skipped regardless of it's activity level.

If previous xfer socket was disconnected, the 'ret' variable wasn't cleared
when the current socket is inactive. The outcome of this is that the
innocent transfer could be discarded.

Thanks to Jonathan Hoppe from Netriplex for discovering this.

- addition fix in ddns.c: disabled assertion. This assertion was
  triggered when removing data from apex node (tested with A record)

Refs #102

refs #111

Refs #102

Refs #102

Refs #102

should be fixing it.

 - Has to be re-enabled after discussion.

Refs #102

Refs #102

There were many conflicts, needs a test.

Conflicts:
	src/libknot/updates/xfr-in.c
	src/zscanner/scanner.c

Only rrset.h conflicts resolved!

Conflicts:
	src/libknot/rrset.h
	src/libknot/updates/xfr-in.c
	src/libknot/zone/zone-contents.c

This is because most of the packet is now not double-buffered,
so query wire is required to remain intact during processing.