nsenter: allow to use --set{uid,gid} for all namespaces

Now it's possible to set UID and GID for user namespaces only. This
patch removes this restriction and allow to use --set{uid,gid} in all
cases. The default for user namespaces is still GID=0, UID=0.

Reported-by: Tomas Doran <bobtfish@bobtfish.net>
Signed-off-by: Karel Zak <kzak@redhat.com>
docs: update TODO

Signed-off-by: Karel Zak <kzak@redhat.com>
fdformat: Add new switches -f/--from, -t/--to, -r/--repair

This commit introduces a support for user configurable
from/to track and a basic repair mode for broken floppies.
It also fixes a recently introduced bug that causes
a line breakage when printing the track number.

Signed-off-by: Karel Zak <kzak@redhat.com>
fdformat: clean up usage()

Signed-off-by: Karel Zak <kzak@redhat.com>