Add icon checkboxes

This adds the icon checkboxes from @orta's design:

![screen shot 2013-11-10 at 13 40 18](https://f.cloud.github.com/assets/749864/1508581/a40efa7a-4a08-11e3-8cc6-9ea41f40008b.png)

Currently the icons turn blue after the install was successful, it might be nice to show some sort of indication that it's in progress but I'm not sure what and how.