Areas no longer sorted

[dracos]

The per-"cobrand" code currently works by importing mapit.countries and having that import a different file. But now global is in this repo, the line was removed from that file and so its own file is no longer imported. We could reinstate the two lines dropped from there (GB is still there for UK, as you can see), but I wonder if there's a better way of registering this file of 'country' specific functions.