Force saltedpasswords for Backend
[FEATURE] ext:saltedpasswords is required and enabled in backend
This patch adds saltedpasswords as a required system extension,
forcing salted hashes to be enabled for backend authentication.
The install tool checks settings and adapts them if needed.
Rsaauth is added to the list of recommended extensions
in the install tool extension installation upgrade wizard.
Reviewed-by: Kai Ole Hartwig
Tested-by: Kai Ole Hartwig
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn