Add operator shelf listing page (bug 1074428)

r? @ngokevin @cvan 

![screen shot 2014-11-03 at 1 17 17 pm](https://cloud.githubusercontent.com/assets/23885/4889569/249bf91a-6397-11e4-94f0-9d5aad71a3c0.png)

We can omit the `href`s.