Oversample Parameter Added to Sega Mega Drive MIDI

I've added another sample playback parameter to the Sega Mega Drive / Genesis MIDI Interface - an 'oversample' parameter. Basically, this is whereby the sample rate of a given audio sample (when channel 6 is in DAC mode) is kept constant, but a determined number of samples (0, 1, 2 or 3) are skipped during playback. The aim here is to give more control over the DAC channel, thereby being able to get a wider range of sounds out of it. Combining the oversample parameter with the playback rate parameter can produce some interesting results.