Stats calculated on finalisation of import
Country geometries for stats are generated during import

This way the stats can be calculated automatically when the import has
finished. The geometry population has to occur before the stats
generation, however it is not dependent on anything else so it can run
as a set of workers.
Finalise job for geometry populator
Merge pull request #104 from unepwcmc/post-import-stats

Stats calculated after import as finished