[lang] update of language files from Transifex

It is been a long time since my last update, so I make a PR first instead of a direct push, to make sure I don't mess up something here. Transifex was constantly updated with the English files, so the translations should be fairly ok and complete.

I'll try to do regular updates from now on. Please let me know, if I can do a direct push next time.

Thanks,
Cheers, Attila