User can log in to recover pre-existing account

[michaelkirk]

Current user system is based on a per device id - this can be blown away be resetting the device. Also it doesn't allow the user to migrate across devices or use the same account from multiple devices.

Although, we want to maintain the ability to play without providing your email or any information, we want to allow the user the option to set their username, email, and password. They can use this to fetch their api credentials.

See wetap for how this might work.