Display images from stacks in search results views

Closes #326 
Closes #338 

#### Default view
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![list-view](https://cloud.githubusercontent.com/assets/96776/3404615/1043250e-fd73-11e3-83b9-e143a9e45d50.png)

#### Gallery view
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![gallery-view](https://cloud.githubusercontent.com/assets/96776/3404619/2024cebe-fd73-11e3-87ef-abce750166eb.png)