- fixed Measuring Tool - after doing a measurement the Notebook was switching to Project Tab without letting the user see the results

- more work on the translation engine; the app now restarts after a language is applied
- added protection against using Travel Z parameter with negative or zero value (in Geometry).

FlatCAMGUI.py

@@ -14,6 +14,10 @@ import webbrowser
 
 from FlatCAMEditor import FCShapeTool
 
+import gettext
+import FlatCAMTranslation as fcTranslate
+fcTranslate.apply_language('FlatCAMGui')
+
 
 class FlatCAMGUI(QtWidgets.QMainWindow):
     # Emitted when persistent window geometry needs to be retained