DeskClock: Update German translation

Screenshot: http://goo.gl/VKzvT

Patch Set 1:    * add missing strings from
                  http://review.cyanogenmod.org/#/c/29894/
                  http://review.cyanogenmod.org/#/c/30664/

Patch Set 2:    * rename strings after comments
                * added screenshot

Change-Id: I4f1a09f9c461c7037268d0685f365d60d912c397
Merge "DeskClock: Update German translation" into cm-10.1