Add matfaust.factparams.ParamsHierarchicalDFT simplified parameter structure...

Add matfaust.factparams.ParamsHierarchicalDFT simplified parameter structure to factorize a DFT matrix with matfaust.fact.hierarchical.

Use case:

import matfaust.dft
import matfaust.fact.hierarchical
import matfaust.factparams.ParamsHierarchicalDFT

d = 32
p = ParamsHierarchicalDFT(log2(d))
DFT = full(dft(d))
F = hierarchical(DFT, p)
norm(full(F)-DFT)/norm(DFT)

% or simply:
F = hierarchical(DFT, 'dft')
norm(full(F)-DFT)/norm(DFT)