Boxplot: set custom percentile or explicit values

[jeffersonsung]

It there a way to customize the box plots instead of max, q3, median, q1, min? I'd like to see the 99.5% and 0.5% so the whiskers and box would size to max, 99.5%, median, 0.5%, min or 99.5%, 1sd, median, -1sd, 0.5%. Basically a customizable percentiles would be nice. Or alternatively just let me submit the 5 values top to bottom and display that.

[etpinard]

Related: #1059

[etpinard]

Merging into #1059