[Muine] Updated groups proposal

[Jorn Baayen <jbaayen gnome org>]

Hi,

I did some minor additions/changes to the groups proposal. It is at the
same location:
http://huizen.dds.nl/~jbaayen/proposal.html

- I added a button in the main UI to open the "playlist filling" stuff.
Not quite happy with this yet ...
- I removed the "Randomize" menu item stuff, as I think it would be
better if we didn't include it- to somewhat forcibly make people aware
of the groups feature (as both features have the same goal- playing
random music of a certain kind. Saves menu clutter, too.)

Jorn