Use a CSS sprite for the license images.

-3 HTTP requests.
Merge pull request #159 from XhmikosR/license-sprite

Use a CSS sprite for the license images.
Specify box sizing.
Clean up unused class and inherited properties.
Use qTip from the first mirror instead of the cloudflare distribution.
Work around issues with old IE.
Remove selectivizr-min.js.

It's not needed anymore as things work pretty good with old browsers.