GeoIP Upgrade: Use legacy data for missing regions

Follow-up of #900

The old regions codes can be found for instance on:
http://fr.openclassrooms.com/forum/sujet/table-pour-les-codes-region-15280#.U3nRaliSyjQ

There you find e.g. the old GeoLite code GB17 for Greater London, which is missing in the latest [regions listing](http://geolite.maxmind.com/download/geoip/misc/region_codes.csv) because it still has [no code](http://statoids.com/ugb.html) in [ISO 3166-2](http://en.wikipedia.org/wiki/ISO_3166-2:GB) and [FIPS 10-4](http://en.wikipedia.org/wiki/List_of_FIPS_region_codes_(S–U)#UK:_United_Kingdom).