Bug Fixes and some new features

The recent introduction of "Discussions" by Github has been very motivating for our users.
Based on their feedback, several enhancement have been implemented.
Here is a selection:

• Most Python functions now have typing / annotation support .
• For PDF table-of-contents items, colors are now supported (reading and writing)
• PDF page label support for reading and writing
• Support personalized tagging of new annotations, fields and links for easier selection of relevant objects.

There also is a number of fixes - please consult the documentation.