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

function saveFigurePosition()
    defaultPosition = get(0,'defaultfigureposition');
    f = gcf;
    defaultPosition(3:4) = f.Position(3:4);
    set(0,'defaultfigureposition',defaultPosition);
end