User can upload photos for a quote

the photo will be stored in S3.

newly added gems:
- nested_form
- carrierwave
- rmagick
- fog

![Screen Shot 2013-02-05 at 12 31 23 AM](https://f.cloud.github.com/assets/184520/124106/c11ad12c-6ee2-11e2-864f-e1c889261af6.png)