Linked content cards experiments

- Timestamp before the link (gives the user an idea on the freshness of the related content)
- Cards have a different title depending on the type of content linked:
    - Comment
    - Video
    - Gallery
    - Related (for simple articles)

We can expect these changes to drive more engagement.

![screen shot 2013-08-08 at 17 57 31](https://f.cloud.github.com/assets/85783/932980/88b9ab90-004c-11e3-8f12-d09eb819b33a.PNG)

![screen shot 2013-08-08 at 17 57 20](https://f.cloud.github.com/assets/85783/932981/8cc85114-004c-11e3-9174-4ec61e0e83f8.PNG)


![Bassdog](http://31.media.tumblr.com/290b2cd826a6c3bbde9fbc60e0541f73/tumblr_mr6edhEcUP1sd2kgbo1_500.jpg)