Use CasperJS for component comparison

Using CasperJS for capturing components.  I can't seem to get it to respect viewports over 600px for some reason, more docs reading required.

![animatedghost1](https://cloud.githubusercontent.com/assets/1492067/4694470/0e1e292a-57ca-11e4-9b5f-be1f1cded35a.gif)

@DaveBlooman Regarding the note on the PR description and it not resizing over 600; is *any* resizing currently occurring? The docs suggest you might have to attach a function and use asynchronously: http://docs.casperjs.org/en/latest/modules/casper.html?highlight=captureselector#viewport

this.viewport(view_port_width, 1500).then(function() {
    // new view port is now effective
});