Listen on externally accessible port

[phkla1]

In testing II locally one would often want to test from another device on the same network. "localhost" is only accessible from the machine running auth-client. If it were possible to have the server listen (either as an option or simultaneously) on 0.0.0.0 (i.e. 0.0.0.0:8080 in this case) then it would be much easier to test with multiple devices and this would greatly improve testing productivity.