prevent sudo-spoofing

Signed-off-by: Mattias Andrée <maandree@operamail.com>
further harden by hardcode the path to sudo

Signed-off-by: Mattias Andrée <maandree@operamail.com>
add ls aliases with --group-directories-first

Signed-off-by: Mattias Andrée <maandree@operamail.com>