Users can add images to personal gallery or dive site

https://trello.com/c/lK9YxAYQ/8-users-can-add-photo

![image](https://cloud.githubusercontent.com/assets/8681076/5107957/1ecdcd58-6fd4-11e4-894f-f69f1ccd6819.png)

![image](https://cloud.githubusercontent.com/assets/8681076/5107951/0b10e138-6fd4-11e4-8d16-dad6bbea1515.png)

un-nest this, and remove the `dive_sites` nested image route completely.