Only RFC 4034 types are converted to lowercase.
Unified the conversion to one RRSet function used in both zone
parsing and packet parsing.

Conflicts:
	src/knot/dnssec/nsec3-chain.c

Dname str params

See merge request !282

Converting to lowercase when saving to zone proved insufficient,
because case-insensitive comparison of RDATA would be needed in some
scenarios - e.g. in IXFR (SOA replacement) and DDNS processing.

Moved the conversion to packet parsing - all dnames in RDATA
are converted to lowercase when parsed from wire. RDATA parsed
from zone file are converted there (in scanner_process()). Later
the conversion may be moved to a lower level of parsing (and with
some option to turn it on/off).

QNAME is unaffected by this change.

Events cleanup

See merge request !286

 - events.c: event manipulation API
 - events-impl.c: zone event implementations
 - events-replan.c: event replanning implementations

Closes #262

Knotc doc

See merge request !285

knotc: dynamic buffer for response

See merge request !284

closes #298

Additional nsec null checks

See merge request !283

fix race during server reload

closes #296

See merge request !281

refs #296

refs #296

closes #293

Conflicts:
	src/libknot/dname.c

Axfr ixfr client

See merge request !280