Function: copyright-update

Update copyright notice to indicate the current year.
With prefix ARG, replace the years in the notice rather than adding
the current year after them. If necessary, and
`copyright-current-gpl-version' is set, any copying permissions
following the copyright are updated as well.
If non-nil, INTERACTIVEP tells the function to behave as when it's called

(fn &optional ARG INTERACTIVEP)