Base charts fail init on IE9 due to CSS 'px' attribute requirement

[peteb4ker]

In IE9, d3.chart.base charts fail to initialize with the following error:

Invalid argument. d3.js, line 32 character 7

This corresponds to the following method in d3:

d3_style_prototype.setProperty = function(name, value, priority) {
  d3_style_setProperty.call(this, name, value + "", priority);
};

Digging into this further, the issue is because height and width CSS styles are being set without a 'px' suffix. The attached pull request fixes this issue. Charts are initialized with width/height "200px" / "200px".