TODO: A way to see the path of the currently selected item in any grouplike
      element. Each item in the path should be a button that, when pressed,
      makes the MAIN grouplike view navigate there.
      (Done!)

TODO: A "shuffle queue" button!
      (Half-way done -- the functionality is there, press "S", but there's no
      button for it yet.)

TODO: A "clear queue" button.

TODO: A way to jump to an item with a particular name. Probably press "/".
      It'd be nice if the closest match got highlighted while you were typing.

TODO: "Queue to play next"... maybe also a cursor in the queue list, which
      would tell after what track to place newly-queued items?

TODO: Scroll to the selected track once it starts playing when selected from
      the queue.

TODO: process.on('SIGWINCH', () => ...) -- detect terminal resize!!
      (Done!)

TODO: Pressing enter in the queue seems to not be doing the right thing?
      It should NOT move the selected item anywhere in the queue; it should
      just select and play that track.
      (Done!)

TODO: iTunes downloader - test this.