Chessa::URI::Default::tcard: work on $published and $modified

scripts/Chessa/URI/Default.pm

@@ -252,8 +252,11 @@ sub tcard($self, $t, $authority) {
     if (defined($author)) {
         $out .= ' ' . $self->{msg}('Author', $author);
     }
-    if ($published ne '') {
+    if (defined($published)) {
         $out .= ' ' . $self->{msg}('Published', $published);
+        if (defined($modified) && ($published ne $modified)) {
+            $out . ' (M: ' . $modified . ')'; 
+        }
     }
     my $size = 420 - length($out);