tags: allow links to page numbers not yet created
Previously, forward references were required to use named destinations.
This patch is based on the patch in #336 (closed) by Guillaume Ayoub guillaume.ayoub@kozea.fr that converted all links to indirect objects written at the end of the document.
I have reworked the patch so that only forward references to future page numbers are written as indirect objects. Backward references and named destinations remain as they are. This is to minimize the number of objects written to the PDF file.
Fixes #336 (closed)