Every package now has or generates a rootfs_files.txt containing a list
of files that should be packed into the rootfs, their permissions and
their owner.
This gives us fine grained controll over the owners and permissions of the
rootfs files (by generating a squashfs pseudo file).
In subsequent steps, this allows us to remove the deploy/devdeploy split and
actually simplifiy most of the build scripts.
Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
