#248 more emphases on file management

[Casper]

HI,
In the current version v2.0.1 the 'largest window' is the playlist window. It therefore 'feels' like the emphases lies on the building of playlists and playing them.

I would very much like to use A-tunes to manage my files and editing the tags, which is mainly possible in the left-top window.
Could it be possible to get the contents of the left-top window in the 'main' window?