[expert] allow non-root user to shutdown linux

[Darcy Brodie]

Hello
    I know that it isn't a good idea to give normal users root access,
but I need to set up a couple of Mandrake boxes (they will only be in
text mode, as these will be remote terminals to a Unix network) so that
a normal user can shut down without having to login as root.  The
process needs to be as simple as possible, to prevent the user from
messing it up

Thank you

Darcy Brodie