- fixed bug that did not asked the user to save the preferences after importing a new set of preferences, after the user is trying to close the Preferences tab window
- added folder for the Russian translation
- made sure that visibility for TextGroup is set only if index is not None in VisPyVisuals.TextGroup.visible() setter
- RELEASE 8.918
- added a new parameter in Edit -> Preferences -> CNCJob named Annotation Size; it controls the size of the font used for annotations
- made visibility change threaded in FlatCAMObj()
- solved issue #292 where a new geometry renamed with many underscores failed to store the name in a saved project
- the name for the saved projects are updated to the current time and not to the time of the app startup
- some PEP8 changes related to comments starting with only one '#' symbol