Some stuff to make it reproducible

Hi Harald,

Here are some patches that add  a script to make the start of day more easily reproducible, and also to make it able to work on non-btrfs and non-fedora systems (makes a btrfs loopback for working in), so its easier for folks to try out.

Hope you like

Rob 

(p.s. feel free to grab me in #systemd if you want)