wks: New server command --list-domains
* tools/gpg-wks-server.c (aListDomains): New. (opts): Add --list-domains. (parse_arguments): Implement. (main): Ditto. Use only one final diagnostic message. (command_list_domains): New. (check_and_publish): Remove directory creation. (get_domain_list): New. (expire_pending_confirmations): Rewrite using a list of directories. (command_cron): Get domain list and pass to expire_pending_confirmations.
gpg-wks-server --list-domains
is required once to create the sub directories