Forumlar / Cotonti / Localization / Transifex translation service

Weblate looks intriguing with its Git support and being open source, so that we could probably add missing features ourselves. But both services need testing first.

Added 3 hours later:

I would prefer a relatively popular service though and in the current situation we can't run a self-hosted solution like Weblate, so it is out.

Added 7 hours later:

Crowdin has the same problems as Transifex and adds some more: files for multiple locales cannot be imported correctly, so it's out.

I've solved most of the problems with Transifex, there's one thing left: associative arrays in $L['cfg_somename_params'].