Allows passwords, keys and one-time codes to use different data stores

```
Apache allows passwords to be stored different ways - .htaccess file, database, 
LDAP, etc.

Our static passwords should do the same, as well as other things we store 
(codes).
```

Original issue reported on code.google.com by `bkgood...@gmail.com` on 10 May 2013 at 3:30
