Merge !1030: server selection rewrite

NEWS

bench/bench_lru.c

daemon/bindings/cache.c

daemon/cache.test/insert_ns.test.integr/kresd_config.j2

...on/cache.test/insert_ns.test.integr/nondelegated_auth.rpl

daemon/engine.c

daemon/lua/kres-gen.lua

daemon/lua/kres-gen.sh

daemon/worker.c

daemon/worker.h

daemon/zimport.c

doc/lib.rst

lib/cache/overflow.test.integr/kresd_config.j2

lib/cache/overflow.test.integr/world_cz_lidovky_www.rpl

lib/cache/overflow.test.integr/world_cz_vutbr_www.rpl

lib/cache/test.integr/kresd_config.j2

lib/defines.h

lib/layer/iterate.c

lib/layer/test.integr/iter_cname_length.rpl

lib/layer/test.integr/iter_limit_bad_glueless.rpl