fzero_vec, integral_vec and spline are now local functions in Curve. Renamed arcLengthStretch to arcLengthParametrization. Removed plot_derivative. Added some comments and extra lines + removed unneccesary lines. arcLength is now a method and not static. Constructor does not accept difference operator anymore.

% Prints the version and location of the sbplib currently in use.
function sbplibVersion()
    scriptname  = mfilename('fullpath');
    [folder,~,~] = fileparts(scriptname);

    name = 'sbplib';
    ver = '0.0.x';

    fprintf('%s %s\n', name, ver);
    fprintf('Running in:\n%s\n',folder);
end