Fixes to German translation

Thanks to Cocoaforge user fxr for spotting this and his for contribution <http://forums.cocoaforge.com/viewtopic.php?t=25091&p=135924#p135924>
The committer (whose German notions are quite rusty) hopes that he hasn't broken anything...
Silent a warning
Solves a small annoyance introduced by commit 6a478a6dcf7adf075cc06a210afe5ccddbe42626

The directory ${DERIVED_FILE_DIR} is not created in many configurations, so we pick up another directory for storing a file.
Version notes