Add styles for documents in search results

Closes #431 

* Add styles to documents in `list`, `gallery` and `brief` views

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![image](https://cloud.githubusercontent.com/assets/302258/3535234/ec23c108-07fc-11e4-88ae-66d833517374.png)

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![image](https://cloud.githubusercontent.com/assets/302258/3535243/03fba2fa-07fd-11e4-9c27-0ef0da2d4eca.png)

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![image](https://cloud.githubusercontent.com/assets/302258/3535247/1ac05e4a-07fd-11e4-9dac-5e76c34baa59.png)