Now writes "biquad" corrected values to the filter files
Filters are already corrected as they are read. This caused issues when compared with the design string.
Biquad correction checks for poles outside the unit circle.
It also corrects for poles too close to zero. These poles are made identically zero.
This commit adds biquad correction as the filters are written to file, and also to design string output when the design string is compared to a loaded set of coefficients.