Add general Runge-Kutta class - Add a general Runge-Kutta class which time integrates the solution based on coefficients obtained from a Butcher tableau - Add butcher tableau which returns coefficents for the specified Runge-Kutta method - Remove RungKutta4proper, since obsolete

% Creates a shape from a number of curves. A shape is a cell array of curves.
function s = shape(varargin);
    s = varargin;
end