Patch with bug fix for Mac OS X

Buf fixed on Mac OS X where pymprepss crashed due to trying non-portable things for translation. This is fixed now: translation works if python can find libintl.dylib and otherwise fails gracefully (i.e. no crash).
Thanks to @brianmay for reporting the bug and testing the fix.

Other novelty, a German translation, work of @FriedrichFroebel