Auto confirm root password

These days, a brand new HDK setup starts in the state where root initial password is defined, but the final password needs to be defined (this is done by the seed_fu rake task).

These functional tests would know how to define and confirm the root password from scratch, but don't know how to handle this intermediate state. This forces the user to manually pass it, be it just to confirm the default password or to introduce a new one.

We need at least the functional tests to be at least able to confirm the intended password if it works for initial login up to the final password definition form.

For the sake of it, we could also introduce a distinction between the default initial password (same as HDK default) and the final one in configuration.