Expand to display better detailed diff per nodes

Expand version of #427 and I agree that this is cleaner solution.  

One caveat though, I did limit the size of line diff so user can scroll when diff is too big.  However when scrolling through may cause entire page to scroll when scroll bar hits the bottom of the div.  This was very nauseating.  Below to solutions can possibly explain what I mean.

http://jsfiddle.net/eXQf3/371/ 
http://jsfiddle.net/9Htjw/

I have went with CSS despite the fact that it shifts view little because I want to avoid dom binding as much as possible.

Please let me know if some one disagree with me or if I'm overreacting to small issue...