parseSvg function crashes in IE

[localjo]

I've been noticing this error in Internet Explorer with an application that depends on d3;
Unable to get property 'matrix' of undefined or null reference

I tracked it down to this line. It seems like the problem is almost identical to d3/d3#376. I'm not completely sure what the conditions are that cause consolidate() to return null in my case. My understanding of the internals of d3 and the SVG API are too limited, and my toolset for debugging issues in IE is too cumbersome for me to quickly find out. However, it seems like the solution is the same as the previous d3 issue. Changing line 21 to the following seems to fix the issue for me;
var m = svgNode.transform.baseVal.consolidate() ? svgNode.transform.baseVal.consolidate().matrix : {a: 1, b: 0, c: 0, d: 1, e: 0, f: 0};

I'm not sure if that's the right fix, but I'll open a PR with that fix for now and await feedback.