Bring the documentation for nodedev-list up to date with the latest
code, especially documenting the --active and -all options.
Also add documentation for the nodedev-define, nodedev-undefine, and
nodedev-start commands.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>