allow new OGDAT V2.2 HTML specification file and .gitmodules
add a new folder 'data'

This folder contains IANA types and ISO language codes and a shell script to obtain that data from the internet
fix a test

http://www.example.com/notexisting returns 404, which is ok, instead of 200
add initial V2.2 support
the json-checker can now check against OGDAT version 2.2
add machine readable OGDAT V2.2 specification files
add human readable OGDAT V2.2 specification file (html)