New ticket header, SEO improvements and fixed stuff

Test

• For all you SEO fans, we've now added a "canonical" reference to forum topics when visitors hit an old URL. This typically happens if you change the name of a topic, but have it linked elsewhere or visitors have it bookmarked. This will tell search engines which URL is the preferred URL, thus reducing the problem of duplicate content.
• Widgets can now have a "Show to non-logged in users" option. This means you now have more control over who has visibility over your widgets.
• MindTouch, an excellent social knowledge base app, is now integrated into Zendesk. You can find out more on our blog, and get your free MindTouch license.