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This PR is introducing 'Less ...' button for the homepage.

After:
![screen shot 2014-11-10 at 16 29 13](https://cloud.githubusercontent.com/assets/2579465/4992315/b134a2be-6996-11e4-9e35-9266c8e2e15b.png)

Question: do we need :focus and :active states for buttons? It just made me to override it in CSS which is really ugly.
chain these...

```
$button.attr('data-link-name', buttonText[state])
    .toggleClass(...
```