Comment # 15 on bug 931571 from Arvin Schnell

Instead of downsizing snapper to a state where we can just not install it
any longer we should fix our base tools:

1. 'df' does not work for btrfs.

2. the output of 'btrfs fi df' is incomprehensibly.

3. 'zypper' does not take into account that on btrfs with snapshots
   overwriting files does not give back the disk space of the old file. So it
   should not report "additional 7.9 KiB will be used" when likely several
   hundreds MiB will be used. (AFAIK this was fixed by now.)