Chun-Yu's Smooth Overdrive Effect

This plugin is pretty simple.  No parameters or attributes.  Just use it for a cool sound, especially when you hook it up to my TouchWah effect (but be sure to use the ScaleFactor or it'll clip!).  What this plugin does:

Overdriven data is produced by
	Sin transform (mapping the amplitude to the Sin curve between 0 and PI/4)
	Quantize -> 4-bit
	Ln transform (similar to Sin transform, but different.  I somehow came up with this one day while writing a Winamp DSP plugin)
	Quantize -> 3-bit
then, 
(sqrt(overdriven*original)+(overdriven+original)/2)/2

The square root part takes the proper sign from the original WAV data.

The Sin and Ln transforms each use tables, so they shouldn't use too much CPU time.  I know the last stop does take some CPU time, and I'll try to fix it soon.