autoscaling width

[SirZach]

If I set {{#nf-graph width="100%"}} this works okay but when trying to combine that with an {{nf-bars}} things go awry and the bars end up stacked on top of each other.

[benlesh]

nf-graph doesn't support percentage based widths for a variety of reasons discussed here #49

We may in the future support this, but it's not likely to work well in some browsers, and could be computationally expensive, depending on how it's implemented.