Merge branch 'serve-stale-rcache-v1' into 'master'

bench/bench_lru.c

daemon/bindings.c

daemon/engine.c

daemon/engine.h

daemon/lua/kres-gen.lua

daemon/worker.c

lib/cookies/lru_cache.c

lib/generic/lru.c

lib/generic/lru.h

lib/nsrep.c

lib/nsrep.h

lib/resolve.c

lib/resolve.h

lib/rplan.h

modules/serve_stale/serve_stale.lua

modules/stats/stats.c

tests/test_lru.c