Add option to quickly/easily display audio URL for tracks in a given playlist

[g-i-g]

Currently in the playlist editor, you have to click the "View track information" button to get the URL of the audio file that's going to be played. It'd be neat if there were an option to display this somewhere near the track without having to click that button (I was thinking just an extra "row" of space where the URL would go, but mm suggested a tooltip/mouseover, which might be nicer).

This would make it easier to check that a playlist is sorted (e.g. Doncasts where all of his audio is 01, 02, 03... .mp3) without having to perform a bunch of extra mouse clicks.