Add password complexity hints

[ChrisEdS]

Steps to reproduce

1. Setup password policy
2. Create a guest user
3. Set password

Expected behaviour

With this pull request we introduced password policy hints on the server side: https://github.com/owncloud/password_policy/pull/335

The same behaviour should be also implemented for the guest account.

Actual behaviour

No hints will be shown when creating the guests password.

The hint is showing up one-by-one after setting a password:

[ChrisEdS]

We should then make the upper and lower case uniform right away.

vs and