Now that creds are processed even if systemd.firstboot=no is set, we can
use it to disable the root pw prompt *and* the new homectl prompt at the
same time, without breaking the creds stuff.
- Use mkosi.images/ instead of mkosi.presets/
- Use the .chroot suffix to run scripts in the image
- Use BuildSources= match for the kernel build
- Move 10-systemd.conf to mkosi.conf and rely on mkosi.local.conf
for local configuration
Luca Boccassi
Lennart Poettering
Richard Maw
Daan De Meyer