Features:
+* man: maybe use the word "inspect" rather than "introspect"?
+
* introduce machines.target to order after all nspawn instances
* systemd-nspawn@.service should fail if some nspawn arg is invalid, with Type=notify
* networkd:
- add LLDP client side support
- - ipv4ll with multiple interfaces doesn't work when both dhcp and
- ipv4ll is used. for some reasons the kernel will currently pick an
- ipv4ll source address to reach non-ipv4ll gateways.
- - dhcp and ipv4ll should probably be skipped for "lo" devices, even
- if the user has a catchall .network file installed, that might
- theoretically match it.
- the DHCP lease data (such as NTP/DNS) is still made available when
a carrier is lost on a link. It should be removed instantly.
- .network setting that allows overriding of the hostname to send to the dhcp server
- implement reconfigure support, see 5.3., 15.11. and 22.20.
- implement information request, see 1.2. and 18.1.5.
- implement support for temporary adressess (IA_TA)
- - implement elapsed time option
- implement dhcpv6 authentication
- investigate the usefulness of Confirm messages; i.e. are there any
situations where the link changes without any loss in carrier detection