Update source fetching

[ronaldtse]

The GeoNames server has been updated and we need to pull files now from this page: https://geonames.nga.mil/geonames/GNSData/

[ronaldtse]

Finally we get back to this task.

This is the page that provides all listings:

• https://geonames.nga.mil/geonames/GNSData/

(some countries are blocked, VPN may be necessary)

Click on "All_countries" or "Whole_world" to obtain the link to data:

• https://geonames.nga.mil/geonames/GNSData/All_Countries.7z

This is the data dictionary used:

• https://geonames.nga.mil/geonames/GNSSearch/GNSDocs/pdfdocs/GNS_Data_Dictionary.pdf

This page provides all the data they use:

• https://geonames.nga.mil/geonames/GNSHome/reference.html#schema

All_Countries.7z contents

So we need to update this repository to accommodate this new file, and update the current Makefile.