implement `listen on' Listening by default on all the addresses is so bad I don't know why I haven't changed this before. Anyway. Add a `listen on $hostname port $port' syntax to the config file and deprecate the old "port" and "ipv6" global setting. Still try to honour them when no "listen on" directive is used for backward compatibily, but this will go away in the next next version hopefully. At the moment the `listen on' in server context don't filter the host, i.e. one can still reach a host from a address not specified in the corresponding `liste on', this will be added later.

rename client->addr to raddr (remote address) and keep original length

typo; use the `l' variable not `len'

add missing -include of *.d files

drop debug log

remove the new_*() declarations that were moved to utils.c

use host->domain to report errors, $2 is free'd

sort pledge promises as per pledge(2)

drop `proc' pledge in the main process unlike the name might suggest, proc_kill() doesn't use kill(2) so proc is not needed.

add `release' target

more avoiding of void pointer arithmetics This time with a temporary variable to avoid not to trigger -Wpointer-sign, sigh.

simplify check brought to my attention by gcc who isn't smart enough to figure out that `ret' is always set.

enable -Werror on CI -Wno-deprecated-declarations is needed because of OpenSSL 3 (and macos stupidly deprecating daemon(3) in favour of that trash of posix_spawn.)

drop questionable #warning

rework the configure script now it resembles less oconfigure and more the configure scripts I'm using in my recent projects. I'd argue it's more easy to use it.