GSH authentication

GSH could authenticate users so that the logged in user id is populated in user audit log entries.

This needs to work with cron/systems who arent logging in. Perhaps sites would want to turn this off. Maybe it is or is not password protected (could have Java kerberos or something).

The intent is not to protect malicious users, but to capture who is making changes to the register.

Note the user id in the OS is already captured, though the user could be acting as another user (e.g. sudo su - grouperuser)

this is a Jira for Grouper 1.6+ potentially.

Chris