Removed ahtable from the codebase.

Knot.files

src/Makefile.am

src/common/hattrie/ahtable.c

src/common/hattrie/ahtable.h

src/knot/server/xfr-handler.h

src/knot/zone/estimator.c

src/libknot/dnssec/zone-sign.c

src/libknot/dnssec/zone-sign.h

src/libknot/zone/node.c

src/libknot/zone/node.h