- replaced the testing if instance of FlatCAMObj with testing the obj.kind attribute

- removed the import of the whole FlatCAMApp file only for the usage of GracefulException
- remove the import of FlatCAMApp and used alternate ways
- optimized the imports in some files
- moved the Bookmarksmanager and ToolDB classes into their own files
- solved some bugs that were not so visible in the Editors and HPGL parser
- split the FlatCAMObj file into multiple files located in the flatcamObjects folder and renamed the contained classes with names more suggestive
- updated the Google Translation for the German language

flatcamEditors/FlatCAMExcEditor.py

@@ -3039,7 +3039,7 @@ class FlatCAMExcEditor(QtCore.QObject):
         Imports the geometry from the given FlatCAM Excellon object
         into the editor.
 
-        :param exc_obj: FlatCAMExcellon object
+        :param exc_obj: ExcellonObject object
         :return: None
         """
 
@@ -3115,7 +3115,7 @@ class FlatCAMExcEditor(QtCore.QObject):
         """
         Create a new Excellon object that contain the edited content of the source Excellon object
 
-        :param exc_obj: FlatCAMExcellon
+        :param exc_obj: ExcellonObject
         :return: None
         """