quarterto/Elessar — pull request #56 by quarterto (2014-06-26 15:39:14+00:00)
Title: Configurable background marks

Should add `bgMark` to replace/supplement `bgLabels`, it's an object with:

* `count`, does what `bgLabels` does now
* `interval`, adds a mark per value interval
* `label`, optional function `Value → String`