(MESS) nes: added Karaoke Studio inputs, mapped to keys Z, X, C. you can
now select songs and see the animation, even if I would not call playable the
games this way. [Fabio Priuli]

out of whatsnew: the expansion slot is currently hacked around at loading time. 
I will soon implement it as a subslot, but I still need to check a few details first.