Fit multigaussian to cauchian

The Cauchian is O(λ⁻²) and it will possibly serve as such a component of the LSF model that will fit the skirts of the LSF. The problem of the Cauchian is that it is not easy to blur it with the Gaussian.

One solution to this problem is to approximate the Cauchian by a linear combination of many Gaussians. Having payed years of CPU time, approximation of a few 10⁻⁷ L² distance has been achieved with a combination of 25 Gaussians. The best approximation is still being updated.