Adds image item view and mods display support

Fixes #142 and fixes #143 

Leaves index view fill out for a later ticket with design/mocks completion.  Fills out mods partials based off of requirements in #143 with some exceptions outlined in #160 . Also pending tests for `related_items` and `language` as I was unable to get them to display (#163).

![screen shot 2014-05-28 at 10 08 01 pm](https://cloud.githubusercontent.com/assets/1656824/3114245/518f2e44-e6ef-11e3-8714-2966fd4911ae.png)