doc: update the copyright years that match $DEBFULLNAME

app: dpkg-copyright

--- code
my @l = localtime;
my $year = $l[5]+1900;
my $oldyear = $year - 1;
my $name = $ENV{DEBFULLNAME};

# $root is provided by App::Cme::Command::run
foreach my $file_node ($root->fetch_element('Files')->fetch_all) {
    my $cop = $file_node->fetch_element_value('Copyright');

    # append current year
    $cop =~ s/(\d+),?\s+$name/$1, $year, $name/g;

    # suppress duplicate current year (for idempotency)
    $cop =~ s/$year, $year/$year/g;

    # create ranges with new year when needed
    $cop =~ s/-$oldyear,\s*$year,?\s+$name/-$year, $name/g;
    $cop =~ s/$oldyear,\s*$year,?\s+$name/$oldyear-$year, $name/g;

    $file_node->store_element_value(Copyright => $cop);
}
---

commit: updated copyright year of $DEBFULLNAME
