Redis Server URI correct parsing

Including password support.

Some PaaS give you full-blown URIs to configure Redis (and other servers) - up until now the URIs were not parsed due to a bad condition in normalizeServer and there was no support for URIs containing a password anyway. This should fix both.
It is returned because normalizeServer doesn't have access to the resource id / array to store the password. It is not an optimum solution but doing it a different way requires more code to be moved around as both the way the class manages the config internally and its methods don't take into account the fact the password could actually come from the URI of the server and not from a separate config entry.