Copied CanadaProvince to BelgiumProvince

Copied CanadaProvince as start for BelgiumProvince
Added Belgian provinces

And renamed Canada references
Renamed file to use ISO code
Regions + ISO 3166-2 codes

Changed codes to 3-letter ISO 3166-2 codes and added regions. Methods
are now named with "BE".
Added BE enum to test
Added comment regarding regions
Merge pull request #1 from peterdesmet/master

Province codes for Belgium