Usage:
------

1. connect your VSL 1818 AudioBox
2. start VSL on your computer
3. run "python vsl1818.py" on the same computer
4. load http://localhost:8000 in your web browser
5. poke around

You can adjust levels (master, aux3/4, aux5/6, aux7/8), panning,
and the high-pass filter for every channel.

You can name the channels, but the names aren't sent to VSL.  Instead
the names are just used for all the clients connected to this program.

It supports treating the four stereo outputs as eight mono outputs,
which mostly works.  It has to convert between showing you separate
values for the left and right channels and telling VSL an amount of
gain and pan, and not all combinations are possible.  It does pretty
well, but sometimes you'll see a small change in, say, aux3 when you
change aux4.

http://www.youtube.com/watch?v=ciWhHaIoN0A

Details and background: http://www.jefftk.com/news/2012-12-21