Default sort on track number when searching for an album
Previous code was sorting by track for album with unique artist, kinda by chance.
But it was not working when several artists.
Now it's ok, and also nice in GUI because track column is highlighted rather than artist.
(search.js code in manageSort keep working: checked)
Fix dragged row width
json2.js no more required with a decent browser
JSON is native for IE>7, Firefox, Chrome, Opera