Lognormal Helpers

Contains fitting for histogram data on normal and lognormal distributions. Though still requiring the fitting toolbox, the parameters are adapted in such a way that Matlab can actually fit the values (e.g. very small x values)!

Functions return mu and sigma parameter, scaling factor (for non-unit distributions) and goodness of fit.
Additionally included are logn2mean and mean2logn to convert between logn parameters mu/sigma and mean/std value (in contrast to lognstat which returns mean and variance)