A number of improvements:
1. Allow the block to be put in the moodle frontpage and not only in
course pages.
2. Improve language detection.
3. Disallow multiple instances of the block (not sure yet what that
would do in terms of javascript!)
4. In case the block is on the frontpage, a link to the corresponding
course is added.
5. "Infrastructure" for lvNummer identification of courses rather than
lvId.