v041
  - update to the very latest version of plugin_utils.py

v040
  - support both Qt5 qnd Qt6 using the latest plugin_utils
  - properly save plugin app settings between launches
v030
  - fixed inconsistent handling of file paths across platforms
  - moved away from QSettings to use standard bk.prefs to save geometry
  - minor bug fixes
  - fixed crash on exit on some platforms with Qt < 5.14
v020
  - fixed issue with spaces in path names in readium javascript code
  - fixed issue in building query
  - fixed minor typos and cleaned up the code a bit
v010
  - first public release of ReadiumReader plugin for Sigil
