Iss47

Add documentation

Hmmm are you sure about your definition of stochastic least squares problem?

I think you can define an extra step:

(1) Linear Least-Squares - no noise info; pure pseudo-inverse
(2) Weighted Least-Squares - noise information available; weighted pseudo-inverse;
(3) Stochastic Least-Squares - noise info available; a priori phase info available;....