Features:
+* make networkd subscribe to PrepareForSleep(false) and refresh all
+ DHCP leases then.
+
+* when the fstab-generator runs in the initrd, it should create a /dev/null mask for systemd-fsck-root.service, to avoid that the the root fs is fsck'ed twice.
+
* maybe introduce WantsMountsFor=? Usecase:
http://lists.freedesktop.org/archives/systemd-devel/2015-January/027729.html