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.

% Calls the constructor of an object.
% Might be usefull to call the constructor of a subclass object in the superclass
function obj = callConstructor(subclassObj, varargin)
    fun = str2func(class(subclassObj));
    obj = fun(varargin{:});
end