By default, when shutting NM down, systemd will kill everything in its
cgroup. But this can cause problems (eg, NM thinking that dhclient
crashed and then taking down an interface that it would otherwise have
left up). Fix this by setting KillMode=process, which tells systemd to
only kill NM itself, and let NM kill its children.
https://bugzilla.redhat.com/show_bug.cgi?id=876218
This pulls in network.target from NetworkManager.service (and not the
other way round), as suggested and agreed on on the systemd ML:
http://lists.freedesktop.org/archives/systemd-devel/2011-March/001692.html
This also introduces an auxiliary service
NetworkManager-wait-online.service that can be used to order a unit
after the point where the network is available. When this is enabled
with "systemd enable NetworkManager-wait-online.service" the unit
network.target will be delayed until the network is up, which is
suitable for synchronizing NFS mounts and similar to it.
https://bugzilla.redhat.com/show_bug.cgi?id=692008
