Initial version of libgames-scores

Fake pull request for initial review of libgames-scores.

Hint: scroll down towards the bottom to get to the newer comments.
Also, each time you mark a string for translation, add a comment on the line above to explain where the string appears. The comment will be displayed to the translators and make life easier for them. Normally if a translator gets confused, he will guess, and that makes our translations worse.

Our existing code does not always do this, but it should.