This commit integrates debootstrap process in KIWI in a more transparent
way. This refactor makes debootstrap to operate directly over the image
target root tree. This way KIWI can show and parse debootstrap stdout
and also avoids having to copy the created root tree from one temporary
folder to the actual target root tree path.
Related to #1587
Systems using a template tool to generate config files
might not be effective when they see the intermediate
config files we need from the host to let certain package
managers work correctly. Therefore the cleanup code in
kiwi takes care to restore from an optionally existing
template file if no other custom variant is present.
This Fixes bsc#1163978
This commit removes the RootBind.move_to_root method as this can all be
done by using the Path.move_to_root utility method. This allows
to drop the RootBind attribute in PackageManager classes and focus
path manipulation methods into a common utility.
Related to #1281
