Migrations: Do not create a profile_id column in PermissionSet
Accounts: Use full_name instead of first/last name
Accounts: Implement User.display_name
Accounts: Move gravatar_url() to User model
Accounts: Get rid of PootleProfileManager
Accounts: Get rid of the custom Profile admin
Accounts: Move PootleProfile.get_unit_rows to User.unit_rows
Accounts: Move UserForm to accounts.forms
Accounts: Move User.post_save logic to accounts

This lets us avoid a call to get_user_model() before the app registry is ready.
pootle_store: Pass User instances instead of PootleProfile wherever possible
Store: Use user instead of profile in get_alt_src_langs()
Accounts: Get rid of some unnecessary calls to get_profile()
Store: Get rid of PootleProfile foreign keys (Part 1)
Store: Get rid of PootleProfile foreign keys (Part 2)
Store: Get rid of profile usage in templates
Stats: Use User instead of PootleProfile when calling stats
Accounts: Get rid of request.profile
Accounts: Get rid of now-unused get_profile() helper
Accounts: Move profile columns and data to User
Accounts: Get rid of Profile.fullname in favour of User.full_name