[ease-dev] Charting.clear() prevents plot rendering

[Ian Mayo <ian@xxxxxxxxxxxxxx>]

There's a code example on the "Code and me" blog-site:
http://codeandme.blogspot.com/2015/04/live-charting-with-ease.html

When re-using this sample code, the clear() call prevents the graphs
from being populated.

Removing the clear() calls makes the demo code work correctty.

Yes, I wish I was also providing a patch. Let's wait & see.