"Authentication Code" is password while "Username" is authentication code

There are 2 fields which have wrong title and hints:
1. Authentication Code: It is actually just the password (in case username is provided).
2. Username: It is actually an oauth/token/username.
Note: Password field should be below username (interchange their positions).
Fix: Provide better names and hints.

Proposing:

Authenticator: for username / oauth / token.
Password: for password.