Ok, code is now fully functional and finished.
You can find it in bitbucket repository, revision 55.
Next steps are:
- finish migration tool to work in both directions: fs2db and db2fs
- adapt "icons" tool to handle in-filesystem thumbnails
- write some documentation
- adapt DR800+ installer to run migration tool, both for installation and also for uninstallation
- release a new version of DR800+