novus/nvd3 — pull request #439 by HenningM (2014-02-07 12:40:56+00:00)
Title: Remove chart when no data is available

I'm using nvd3 to visualize real time data, and I've noticed that the chart is not removed when there is no data available.
![nvd3_nodata](https://f.cloud.github.com/assets/200462/2109637/e896fbe4-8ff3-11e3-8510-ea1f6ca80b78.png)