flattenStruct2Cell

Takes a Nested Structure, and returns a linear Cell array

% Extention of struct2cell
% Takes a (possibly) nested structure and returns a linear cell array
% containing all the elements of the structure and another cell array
% containing the names of elements
% usage I is a structure
% Input
% cellstack is the array of non-structure elements
%
% Output
% cellnamestack is the name of the element including the path through the
% hirearchy