Precision threshold should be stored as a square
Changed all filters to use double values (not float).

Fixed the width filters to parse initialSD0 from the configuration
string.
Added more method for ML precision and variance
All the threshold that are compared to the peak result data should be
floats since the raw data is stored as a float.
Switch from using getPrecision to getVariance to avoid sqrt()
Change filter to use variance instead of precision for speed