Add a new type of chart, "Line Plus Stacked Bars"

Hello, Sorry about my English...
I was Investigating, about, how to do Line + MultiBar and those bars are "stacked"m using of course, nvd3,
i could not do it, so i change a little the nvd3.js, and using the "LinePlusBarChart", I created "LinePlusStackedBarChart". If you see, I'm not the only one, who wants to make that type of chart, so I make a Fork of this project to share what i did.