Pass scheme specific parameters as cell array. This will enabale constructDiffOps to be more general. In addition, allow for schemes returning function handles as diffOps, which is currently how non-linear schemes such as Burgers1d are implemented.

function s = stuffStruct(varargin)
    s = struct();

    for i = 1:nargin
        assert(~isempty(inputname(i)), 'All inputs must be variables.');
        s.(inputname(i)) = varargin{i};
    end
end