Features:
* resolved:
- - CNAME resolver
- - cache
- - IDN
+ - IDN (?)
- DNSSEC
- LLMNR
- mDNS/DNS-SD
- DNS-SD service registration from socket units
- port sd-resolve to direct bus calls
- nss module: fallback to glibc dns modules if resolved cannot be contacted
+ - edns0 + dname
+ - cname on PTR (?)
+ - negative caching
* Allow multiple ExecStart= for all Type= settings, so that we can cover rescue.service nicely