Users should be able to add additional credentials:
Users with email credentials should be able to add a Facebook credential so they can sign in using Facebook as well, should they find that easier.
Users with Facebook credentials should be able to add email credentials, should they wish to stop using Facebook.
When a user has email credentials, he/she should be able to delete his/her Facebook credentials.
When a user has both credentials, we shouldn't auto update the user's profile when signing in with Facebook as they may have overwritten these, assuming #77 is implemented.
Users should be able to add additional credentials:
When a user has email credentials, he/she should be able to delete his/her Facebook credentials.
When a user has both credentials, we shouldn't auto update the user's profile when signing in with Facebook as they may have overwritten these, assuming #77 is implemented.