Merge !600: NSEC3 aggressive caching

NEWS

contrib/base32hex.c

contrib/base32hex.h

lib/cache/api.c

lib/cache/entry_list.c

lib/cache/entry_pkt.c

lib/cache/entry_rr.c

lib/cache/impl.h

lib/cache/nsec1.c

lib/cache/nsec3.c

lib/cache/peek.c

lib/lib.mk

lib/nsrep.h

lib/resolve.c

lib/utils.h