The old "systemd-import" binary is now an internal tool. We still use it
as asynchronous backend for systemd-importd. Since the import tool might
require some IO and CPU resources (due to qcow2 explosion, and
decompression), and because we might want to run it with more minimal
priviliges we still keep it around as the worker binary to execute as
child process of importd.
machinectl now has verbs for pulling down images, cancelling them and
listing them.
I figure "pull-dck" is not a good name, given that one could certainly
read the verb in a way that might be funny for 16year-olds. ;-)
Also, don't hardcode the index URL to use, make it runtime and configure
time configurable instead.
