- the application now uses only the default values from the app.options dict, the app.defaults dict holds the definitive default values

- fixed some outstanding issues from the PyQt6 port
- PEP8 fixes
- minor fixes
- updated the saving of Preferences to update the self.options too: the `Apply` action will update the self.options but the `Save` action will save the updated preferences to the file on disk

tclCommands/TclCommandExportDXF.py

@@ -61,7 +61,7 @@ class TclCommandExportDXF(TclCommand):
         source_obj_name = args['name']
 
         if 'filename' not in args:
-            filename = self.app.defaults["global_last_save_folder"] + '/' + args['name']
+            filename = self.app.options["global_last_save_folder"] + '/' + args['name']
         else:
             filename = args['filename']