added ./R/HoltWintersNew.R, basic functions with filter and parameter...

added ./R/HoltWintersNew.R, basic functions with filter and parameter initialisaton. I only consider for case with all level, trend and seasonal, have not consider the case without trend or seasonal, have not considered the mutiplicateive case, still need polish and test. You could test it first and give me some suggestion if you have time. Thanks