Cover Photos

I'd like to be able to upload cover photos for profiles. Maximum size should be something like 600x130, not too big. There will need to be a new LDAP attribute added. Cropping should also work, using similar code to profile picture cropping.

I don't like the idea for storing something so specific to this application in LDAP. The images should be stored on S3 and their IDs stored in a simple SQL DB.