[CM] snd: mouse scroll up/down - zoom in/out (in gnome/gtk?)

[bil at ccrma.Stanford.EDU]

I can only find 5 buttons in gdk-enums.h, and I can't
remember what those 5 mean.  I'd try googling "gtk
scroll wheel" and see if anything useful is out there.
"GdkScrollDirection" for example.  Good luck.