tree-wide: remove Emacs lines from all files This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.

resolved,networkd: unify ResolveSupport enum networkd previously knew an enum "ResolveSupport" for configuring per-interface LLMNR support, resolved had a similar enum just called "Support", with the same value and similar pasers. Unify this, call the enum ResolveSupport, and port both daemons to it.

resolved: introduce a dnssec_mode setting per scope The setting controls which kind of DNSSEC validation is done: none at all, trusting the AD bit, or client-side validation. For now, no validation is implemented, hence the setting doesn't do much yet, except of toggling the CD bit in the generated messages if full client-side validation is requested.

resolved: add a generic DnsSearchDomain concept With this change, we add a new object to resolved, "DnsSearchDomain=" which wraps a search domain. This is then used to introduce a global search domain list, in addition to the existing per-link search domain list which is reword to make use of this new object too. This is preparation for implement proper unicast DNS search domain support.

resolved: unify code for parsing dns server information Let's use the same parser when parsing dns server information from /etc/resolv.conf and our native configuration file. Also, move all code that manages lists of dns servers to a single place. resolved-dns-server.c

resolved: rename resolved.h to resolved-manager.h After all it pretty much exlcusively containers definitions about the "Manager" object, hence let's call this the most obvious way.

resolved: beef up DNS server configuration logic We now maintain two lists of DNS servers: system servers and fallback servers. system servers are used in combination with any per-link servers. fallback servers are only used if there are no system servers or per-link servers configured. The system server list is supposed to be populated from a foreign tool's /etc/resolv.conf (not implemented yet). Also adds a configuration switch for LLMNR, that allows configuring whether LLMNR shall be used simply for resolving or also for responding.