go-gl/glh — pull request #46 by pwaller (2014-07-13 18:43:09+00:00)
Title: Add DrawAxes() for diagnosing coord-sys issues

Looks something like this:

![screenshot from 2014-07-13 19 40 37](https://cloud.githubusercontent.com/assets/438648/3565510/83bdb290-0abd-11e4-8262-86795ccbc0cd.png)