HackerNews: add fuzzy date to tiles

Fixes #902 

![screenshot - 07202014 - 02 05 42 pm](https://cloud.githubusercontent.com/assets/4411471/3638162/82f554d2-1038-11e4-9065-715b9201b96f.png)

So, I'm using a fuzzy (relative) date (i.e. "5 months ago" instead of "3/14/14"), which is more friendly to read, but I realized that this might not work for translation/i18n. Thoughts?

Also, I don't love what the metabar says. Maybe "Showing 20 2048 Hacker News (items|posts)" would be better?
cc @moollaza 

**Edit:** Silly me, I used "Timer" instead of "HackerNews" in the commit...
**EditEdit:** ...so I did an interactive rebase and amended the message.
It looks like @jagtalon had commented it out a while ago because it was too harsh. I haven't seen any bad results with HN so I think it's safe to remove the comment. If we find it needs to be added back we can always do that.