- fixed some issues with using the exec_() which now should be exec()

- added a context menu action in the canvas context menu for moving selected objects to origin

FlatCAM.py

@@ -167,4 +167,4 @@ if __name__ == '__main__':
     timer.start(100)
 
     sys.exit(app.exec())
-    # app.exec_()
+    # app.exec()