We don't currently have a tool in place for converting the existing translation files. And with as many text changes and additions throughout the interface as we've had, the previous translation files may be too outdated for continued use.
That being said, we're still working on finalizing the new English language file to include all of the new translation strings, get rid of any duplicates, eliminate redundancies, reduce the amount of text that needs to be translated, make the file simpler to use and translate, and a variety of other things. The English language file will be ready for translating around the time of the first minor version update. We will keep you posted as things become more finalized!