[Xfce-i18n] German translation updates plus libxfconf

[Fabian Nowak]

> Why being in a hurry?
> I thought about working heavily on the German translation once the
> string freeze for 4.6 happened, I guess it will be in a few weeks.
> Waiting for the string freeze would make it easier because then we
> don't have to expect further changes :).
> 

Just my current state of my personal translation progress and desire to
have my currently installed programs translated.

Besides, the hurry arises from people already targeting first alpha
releases - I don't like them being English language only or translated
half way only.

Good night

Fabian