Loop Crossfade amounts are fixed

So it turns out that loop crossfade points in EXS files are stored in milliseconds, not samples. This is a major bummer for folks writing a converter because both SFZ and DecentSampler expect all of their loop values to be in samples. The only way to convert is to actually peak into each audio file, look at its sample rate, and do the calculation. This work is now being done by this converter.