Ensures that the favorite-tracks and artist column consume the remaining space to ensure they are the same height.

* This is quite tricky to do nicely, but this hack using CSS tables seems to work
* Solution taken from http://stackoverflow.com/questions/19695784
* Also added a missing </div> tag which was stopping this approach from otherwise working
Adds some box-shadow to the artist avatar and artist tracks to make the UI more consistent.
Some UI improvements to artist track elements - including a larger play icon.