- trying to separate the Preferences settings from App init and to make them dependent on the self.defaults dictionary
- updated the language strings from the source
- fixed issue in the Excellon Editor where the Space key did not toggle the direction of the array of drills
- combed the application strings all over the app and trimmed them up until those starting with letter 'O'
- updated the translation strings
- updated Drilling Tool to use the new settings
- updated the Excellon Editor: the default_data dict is populated now on Editor entry
- Excellon Editor: added a new functionality: conversion of slots to drills
- Excellon UI: added a new feature that is grouped in Advanced Settings: a toggle tools table visibility checkbox
- fixed the issue with factory_defaults being saved every time the app start
- fixed the preferences not being saved to a file when the Save button is pressed in Edit -> Preferences
- fixed and updated the Transform Tools in the Editors
