NR: no working links in included PDFs

[Werner LEMBERG]

Look at the documention of `\with-url` in the PDF version of the NR:
The link in the included snippet (to 'lilypond.org') doesn't work.
This is a limitation of pdfTeX (or XeTeX), which drops all links and
annotations for included PDF files.

Masamichi-san, is it possible to extend `extractpdfmark` to cover
this, too?  Looking around it seems that the tool 'pax'
('PDFAnnotExtractor') in TeXLive can do that.  However, it is based on
Java...

  https://github.com/bastien-roucaries/latex-pax

The reason why I ask is the planned inclusion of the Visual Grob Index
in the NR – all grobs shown have links to the corresponding
documentation.  If these links are lost the value of the index is
reduced enormously, and it would be probably better to not include it
at all but to have a stand-alone, simple, two-page document instead.


    Werner