[TASK] Implement check for saltedpasswords in reports module

The reports module should show a warning, if saltedpasswords is
not installed or not configured correctly.

Change-Id: Icbd31378a05f02f20de5e43a63465c119f72a6d3
Resolves: #30695
Releases: 4.6, 4.5
Reviewed-on: http://review.typo3.org/6275
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers