FU: Revert integration with XMLWriter & import options; copyright stuff

Realized that, since html_() now returns a string, it's just as easy to
just pass that to fu->set_body(); no need for integration complexity.

Combined import options don't save much typing, not worth the overhead
either.

FU/Util.pm

@@ -312,3 +312,11 @@ for more weirdness and edge cases.
 
 See also L<IO::FDPass> for a more portable solution, although that one does not
 support passing along regular data.
+
+=head1 COPYRIGHT
+
+MIT.
+
+=head1 AUTHOR
+
+Yorhel <projects@yorhel.nl>