- No EDNS processing when server's OPT is not set
- Clearing OPT from packet
- Fixed packet unittest (wrong condition)

Conflicts:
	tests/Makefile.am

TODO: unittests

- Removed EDNS params structure.
- Server now stores the OPT RR itself.
- Removed all EDNS manipulation from packet.
- Cleaned up some EDNS-related packet-checking functions.

Removed some questions and replaced with empty functions left for
implementation, see the #warning lines and implement them.

- old tests dropped, will be useful in rdata_t and knot_rdataset_t
  tests.

Conflicts:
	tests/fake_server.h

Conflicts:
	src/knot/nameserver/process_query.h
	src/knot/server/udp-handler.c
	src/knot/server/zone-load.c
	src/knot/zone/zone.c

This reverts commit f4de5482.

refs #239

Conflicts:
	src/knot/server/udp-handler.c

This reverts commit 4847e1ba.

Mostly wrong test counts.

In the pkt tests, the comparison test is failing, but don't know
why. It's somehow related to the OPT RR, because when I remove its
addition, it doesn't fail anymore. However, I don't know what's
the problem yet.