Results 5 issues of hiroki fujiwara

fixed issue https://github.com/Androguide/HoloGraphLibrary/issues/26 and this difference can clicked stacked bargraph.

The argument of OnBarClickedLister.onClick was wrong, when I clicked BarGraph on HoloGraphLibrarySample. if I click Test1 Graph, index value is '0'. if I click Test2 Graph, index value is '-1'....

the first letter of the method name should be in lowercase. Bar.AddStackValue changed to Bar.addStackValue.

Ruby1.9で実行すると「 invalid multibyte char (US-ASCII) (SyntaxError)」ってエラーがでました。 修正よろしくお願いします。