Change username
All usernames are irreversibly-encrypted before storing the data with bcrypt + shared salt.
Success! Your new username must be used from now on
Error! Invalid or duplicate new username
Error! Your current password is invalid
Error! Something went wrong submitting the form
Error! Invalid new username length
Error! Somebody else is using that username
Error! This form was not submitted correctly
Error! Invalid value(s) were posted to the server