Camera: Update German translation

Patch Set 1:   * add missing strings
               * shorten 'Megapixel' to 'MP'
               * some cleanup

Patch Set 2:   * revert 'Megapixel' shortening

Change-Id: I07b0f8ae4deb3b67258595d5046c22933738e657
Merge "Camera: Update German translation" into cm-10.1-staging