Overload numel function in dynSeries and dynDates classes
If ts is a dynSeries object then numel(ts) should return the number of variables (ts.vobs). If dd is a dynDates object then numel(dd) should return the number of dates (dd.ndat).
If ts is a dynSeries object then numel(ts) should return the number of variables (ts.vobs). If dd is a dynDates object then numel(dd) should return the number of dates (dd.ndat).