Imported translation project for Fahrplan from Transifex
Updated German, Ukrainian and Russian translations

Some German translations were fetched from Transifex, contributed by
Florian Wittmann (florianwittmann).
Fetched new translations from Transifex

- Arabic (empty), requested by طاهر  (hisoka512)
- Romanian, contributed by LaurB (laurbb)
Added credits for translations and a link to translate Fahrplan
Merge pull request #116 from leppa/transifex

Using Transifex for translations