Accounts: Move profile columns and data to User
Accounts: Get rid of Profile.fullname in favour of User.full_name
Accounts: Move PootleProfile.contributions to User.contributions
Accounts: Move profile_edit logic to accounts
Profile: Get rid of PootleProfile model (and its migrations)
Migrations: Update PootleProfile frozen models to point to User
Accounts: Get rid of User.get_profile()