Embed browse plugin

Fixes #29 

Adds embedded browse functionality to an "At the library" show page. JS plugin overwrites the link locations so that non JS browsers will still click through to a link to the browse page.

![screen shot 2014-06-24 at 5 24 36 pm](https://cloud.githubusercontent.com/assets/1656824/3380144/72747400-fbff-11e3-8c9e-59292ef968ef.png)

![screen shot 2014-06-24 at 5 25 01 pm](https://cloud.githubusercontent.com/assets/1656824/3380147/77f0b088-fbff-11e3-8d58-00ee96353829.png)

Left and right browse more boxes with links to the original item browse page.

![screen shot 2014-06-24 at 5 25 08 pm](https://cloud.githubusercontent.com/assets/1656824/3380152/9feeff9a-fbff-11e3-8952-f591d5a881c6.png)

![screen shot 2014-06-24 at 5 25 14 pm](https://cloud.githubusercontent.com/assets/1656824/3380154/a3be71be-fbff-11e3-992f-a8961227b30f.png)


Ah, okay, I didn't notice the index there.  Perhaps we can add that in an options hash to the helper?  I'm not aware of anywhere else this is going to get linked at the moment, so keeping it out of the view now seems like a good approach.