Repairs the limited request tests according to the patch in commit a3dd3072

The RRL rate is measured and averaged over a period of time. This
measurement window was applied only for existing buckets. This change
enables this behavior for new buckets as well.

This should have no operational impact. But it will make our testing
a bit easier.

Conflicts:
	Knot.files
	src/knot/nameserver/update.c
	src/knot/nameserver/update.h
	src/knot/server/tcp-handler.c
	src/knot/zone/events.c
	src/knot/zone/zone.c
	src/knot/zone/zone.h
	src/libknot/packet/net.c
	src/libknot/rdataset.c
	src/utils/nsupdate/nsupdate_params.h

- includes not finished yet

The config.h is now implicitly included using -include option of the
compiler. After this change, config.h need not be placed at the first
position in all source files.

also includes removal of knot_ prefixes from private API

close #205

There are still (marked) several leak points, as the names are not
referenced counted now. But this should be addressed as a part of
node/rrset refactoring efforts.

refs #21