canonical tags on the website

[Eitan Adler]

It makes sense to start using <link rel="canonical"> tags on the website
in order to teach Google and other search engines which is the
preferred mirror for duplicate content.

More details here:
https://support.google.com/webmasters/bin/answer.py?hl=en&answer=139394

I don't have a patch as I'm not sure how to generate such links automatically.

-- 
Eitan Adler