Comments:
Line 56-58: "Gegen den Uhrzeigersinn" is shorter and more common than "Entgegen dem Uhrzeigersinn" (http://de.wikipedia.org/wiki/Drehrichtung)

Line 60-63: "Hand-Werkzeug" is also used in Acrobat

Line 124,133,..: "PDF" is not a noun. Acrobat, Wikipedia use "PDF-Datei" (="PDF file") instead of "PDF".
The English translation sounds just as bad: "An error occurred while loading the PDF.", "The PDF is not fully loaded for printing."
Merge pull request #4018 from fkaelberer/l10nUpdatesDE

Update L10n for DE