APU parity
Currently, the APU for web is implemented via methods in the Web Audio API. Aside from this causing slight differences between Chromium and Firefox, it also causes differences between native and web.

I think rewriting the web APU to be sample buffer-based like the native one would be a good idea. It would ensure that audio sounds exactly the same, and would make porting features between the two implementations much easier. I also suspect a sample-based implementation would make solving #308 easier.

Thoughts?