Features:
+* add bus api to query unit file's X fields.
+
* consider adding RuntimeDirectoryUser= + RuntimeDirectoryGroup=
* sd-event: define more intervals where we will shift wakeup intervals around in, 1h, 6h, 24h, ...
- add support for more attribute types
* networkd:
+ - make sure RTM_NEWLINK messages match both the ifname and kind when setting the ifindex of a netdev
- add more keys to [Route] and [Address] sections
- add support for more DHCPv4 options (and, longer term, other kinds of dynamic config)
- add proper initrd support (in particular generate .network/.link files based on /proc/cmdline)