show query time and total number of shuffle in viz

Show query time and total number of shuffled tuples in the first page of visualization.

solve #136 

![screenshot 2014-06-15 14 41 17](https://cloud.githubusercontent.com/assets/720571/3282080/d36144ea-f4d5-11e3-9fdf-93e2f538422e.png)

Use underscore and reduce? See http://stackoverflow.com/a/14430590/214950