GitLab

added a noiseless wiener filter demo that still needs to be MPI paralized - weighting for more indexing support to do so

added a function that computes the typical signal variance for a given power spectrum. Now the wiener filter easy demo uses this function to set its signal level instead of the even worse practice of letting the user specify a signal to nosie ratio

changed initial value for krylov sampling CG and changed demo to actually use the krylov sampling method supplied by NIFTy