- more fixes in camlib.CNCJob regarding usage of toolchange (in case it is None)
- fixed postprocessor files to work with toolchange_xy parameter value = None (no values in Edit - Preferences fields)
- in case that the Toolchange X,Y parameter in Selected (or in Preferences) are deleted then the app will still do the job using the current coordinates for toolchange
- fixed an issue in camlib.CNCJob where tha variable self.toolchange_xy was used for 2 different purposes which created loss of information.
- the version date in GCode header is now the one set in FlatCAMApp.App.version_date
- fixed bug in postprocessor files: number of drills is now calculated only for the Excellon objects in toolchange function (only Excellon objects have drills)