tick labels obaque background box

[chrisjsewell]

Just a little thing...

As illustrated in the bottom left corner of the image below, particularly when taking screenshots, it would be nice not to have unintelligible text caused by the tick labels overlapping. I imagine this can be achieved by an option for creating opaque boxes behind the text, as in this example: https://stemkoski.github.io/Three.js/Sprite-Text-Labels.html