Boxplot

Creates a boxplot which takes an array containing at least 5 quantiles and then a number for the axis position and a number for the width [[quantiles], axis, width].

```graph
bounds: [-10, 10, 10, -10]
keepAspectRatio: true
elements: [
	{type: boxplot, def: [[-1,2,3,3.5,5], 2, 4]}
]
```