CSSess bug fixes and new features

I finally found the time to sit down and bang out some code for CSSess. You can view the complete list of commits on github but here are some highlights:

• Check for duplicate links
• Ignore additional inaccessible URLs (eg file://)
• Ignore cross site CSS

…and the most requested feature, a toggle checkboxes button to check or uncheck all links.

Your bookmarklet will update automatically since it uses the latest files on github. As always, suggestions and contributions are welcome.