Increased the HTML height to allow for greater seed value entropy

This fixes the "small" height entropy window, because the JS doesn't detect the mouse points outside of the ```body``` tag's content height.

So if the page content is only 50% of the screen's height, you can only use 50% of the available height entropy to generate random seed points.

This commit makes the ```html``` and ```body``` tags have a set height of ```100%``` and fixes this minor issue.

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This is a fixed re-push of pull request #69.