ICON variable is not needed anymore
Add a paragraph in the manpage about sudo options

Mention that you can use sudo options with gnsu.
Plus a few changes here and there.
Fix --help message

Mention that you can run a command as any other user, not only just as
superuser.
Actually make it possible to use a different LIBEXEC_DIR
Remove the path from the comments at the top

It might not be installed in /usr/bin...
Add README file