Use a struct to save all nedeed to equalizer dialgog.
Use the struct to reduce arguments in functions.
Remove gtk_dialog_run()
The equalizer dialog no need to be modal.
Move the handler to menubar.
Show, but ignore the changes in dialog when no has equalizer in backend.
No need save the dialog widget.
D'Oh!. ;)
Bind bands and widgets properties in a sinlge function.
Hide cwin members a bit. At least in the equalizer.
TODO: Extend it.