Core pr 3 (merge with Artesis)

* Updated to use moreInfo service.
* Change from black hole to virtual field.
* Fixed problem with fetching limit on moreInfo when more than 50 covers where requested.
* Updated to use the new library identifier call instead of faust.
* Clean up of JavaScript code.

Other
* Bug report sent to DBC about problem where the new method don't return covers even though the service has a cover with the old method.