Use async call to detect user language in Tabzilla, Bug 1018724

Ah ok, now I see why there might be more than one callback in the array. I should have scrolled all the way down first :smile:

Interesting idea! Part of me does wonder if this functionality is pushing the limits of what Tabzilla should be offering in terms of features though. We should at least consider that this could become a dependency on other people's sites, and something that we would be committed to.