playlist subsystem overhaul

[Nikolaj Hald Nielsen]

> Yes, it's known that graphical finesse is of little importance to you :)

I do actually take some offense to this, seeing as I have actually
done most of the work to tweak and integrate every single theme we
have had so far, including the current one. I know you did not like
most of the previous themes we have had, but I have simply worked with
what I had available.

> Which doesn't even work. Enabling it in combination with transparency
> yields horrible graphical glitches.

Which is a Qt bug that needs to be solved, but not a proof that it
cannot be done.

- Nikolaj