Created attachment cleaner and included all crop urls for images

@jenwachter let me know what you think of this solution. It does what I need for now even though it doesn't allow us to associate only the one crop URL per each image type associated with a person or whatever. I can live with that and just call in whatever I need in the template, though. So if this works for you, cool.

Totally fine with scrapping it and doing it another way though if this causes any problems! I'll just use it for any Backbone stuff I do this weekend and then modify as needed.