User Authentication

This contains the user authentication (provided by Devise) and associating datasets with users.

For claiming the datasets that were created before the user was created - when a user visits an unclaimed dataset, it is assigned to them.

I'm not sure if this is the best way of doing that.  I started storing a list of unclaimed datasets on the user session, though it started feeling a bit cumbersome.

Maybe a nice way to do this would be to have a link on the dataset "claim this dataset" which would take you to sign in or register.