- make /run/lock %ghost to fix build failure

- make /var/run and /var/lock just ghost entries and create them
if they do not exist at all and rely on dracut hooks to
actually replace directories with symlinks there (bnc#874748)

- add vscan user to ignore home list

- change /sys to mode 0555 (bnc#871640)

- make /var/lock a symlink to /run/lock (bnc#867873)

- use lazy umount

- use os.execute("umount ...") instead of posix.umount("...")
bnc#866964

- change pre to pretrans for directory/symlink conversion

- drop /var/lib/pam_devperm (bnc#866234)

- replace /var/run by symlink to /run
- try to handle case where /var/run is a bind-mount
- extend lua script in preinstall to handle this transition
- bnc#865893