Update Locale.de-DE.xaml

Hi,

I just updated the german translation. Also corrected a few errors.

Regards,
Florian

P.S.: I noticed that you credit all people who submit translations and that I am credited, too (by FJunge0901). :-) Could you please change the nick to my full name, which is Florian Junge ? Thanks a lot! :-) And Thank you for crediting me in the first place. :-)