- Fixed DO flag setting.
- Fixed RDATA setting in OPT init. There was some weird problem
  with the allocated dummy RDATA. Using stack instead.
- Flags were not initialized.
- Fixed flag setting in kdig.

- Fixed byte order of TTL - now all manipulations use wire byte
  order, so that the implementation is platform-independent.
- Removed some unused functions and constants.
- Server will use the EDNS parameters structure, it's simpler this
  way.

+ Some cleanup.

ref #209

ref #209

ref #209

- OPT RR is now a normal RRSet.
- Server stores only some EDNS options.
  (Will be changed later back to whole RR.)
- Rewritten EDNS getters and setters to use normal RRSet.
  (Option manipulation not done yet.)
- Added helper function for getting RRSet TTL.

This prevents problems when sharing/reusing the address bytes.

Zero-length msg_namelen prevents this.

 - Simpler DDNS signing, simpler changeset merging (todo: fix leaks)
 - Removed some needles helper functions and zone adjusting

Conflicts:
	src/knot/server/zones.c
	src/knot/server/zones.h
	src/knot/updates/xfr-in.c
	src/knot/zone/contents.c
	src/knot/zone/contents.h
	src/knot/zone/zone-dump.c
	src/knot/zone/zone-dump.h
	src/knot/zone/zonefile.c
	tests/process_query.c

Ttl Tests

ref #158

Ttl Check Fix

More info in the commit message.