Squashed commit of the following:

Note: While I don't normally squash commits, it was worth doing in this instance because some of the intermediate steps contained some sensitive data pertaining to S3. For safety's sake, I didn't want someone to be able to hunt the data down through the Git records.

commit 502a8ceed7384734353e6d11def311a3607ecccd
Author: alexlafroscia <alex.lafroscia@gmail.com>
Date:   Fri May 3 09:03:26 2013 -0400

    User environmental variables instead of the raw access keys themselves

commit 853c4f9557df9058de0a4dff8d7cb64c5e27cdf1
Author: alexlafroscia <alex.lafroscia@gmail.com>
Date:   Fri May 3 08:47:16 2013 -0400

    Change S3 settings by environment

commit 332f9557358a9d73bc202775f87251558ea796c5
Author: alexlafroscia <alex.lafroscia@gmail.com>
Date:   Thu May 2 16:26:02 2013 -0400

    Use S3 for profile pictures