Use google chart instead of NVD3 and simplify code
Small improvements in chart options
Add distribution functions and chart
Code improvements

* external normalization function
* 10 bins
Add box plot with stacked bars

* It can be improved with candlesticks
Use candlestick for box plot
Add number of pieces in statistics table
Add view, computation and functions for intervals
Add intervals basic data functions
Improve intervals frequency code

* Abstract count function
Improve javascript id
Add intervals frequency pie chart
Improve variable name
Abstract pie_chart data generate to function
Add chromatic intervals pie chart
Add chromatic leap chart