Change log:
-Added the ability to disable or enable audio 
-Added cpu speed 5 which is only slightly faster than cpu speed 4, but its there for people who may think it'll help
-attempted to reduce freezing of entering the emulator menu from in game (haven't tested to see if it works)

And that is about it.

With these changes, I have tested that Mario Kart is now playable with sound disabled on cpu speed 4 or 5. Haven't really done any other tests though so feel free to post results here.
