Province codes for Belgium

Codes added for the 10 provinces and 3 regions of Belgium, based on http://en.wikipedia.org/wiki/ISO_3166-2:BE.

*Warning*: this code has not been tested. @cgendreau, could you either test this, or explain (via email) how I can test this locally? I can always add more commits to this pull request.

Once successfully pulled, I'll add different province notations to the narwhal-processor.