Hi Dieter,
Thank you for your contribution, however we currently use WordPress’ GlotPress project for translations and no longer bundle them with the themes. This ensures that several people can contribute to a particular translation and translated strings are also reviewed by an editor familiar with the language, while completed translations automatically become available for those using WordPress in a particular language (even without updating or reinstalling the theme).
I would submit your translation to the project, but I am not sure if it fits under German (default) or German (formal).