Single session module configuration

Concerned version

Version: 2.0.7

Summary

Single session options are highly confusing, and most of them are broken.

Parameter	Name in manager	French name in manager	Description in wiki	Actual effect
singleIP	One IP only by user	One session per (IP,user) pair	Allow only one session per IP	❌ Remove all sessions not matching the current IP on login for the current user
singleSession	One session only by user	One session per user	Allow only one session per user	✅ Remove all previous sessions on login
singleUserByIP	One user by IP address	One user per IP address	Allow only one user per IP	❌ Error 500, removes all sessions matching the current IP on login for all users
singleSessionUserByIP	One session by IP address	One session per IP address	Allow only one session per user on an IP	❌ Not implemented

Suggested fixes

• Rectify label and documentation for singleIP, it's correct in English, but not in French
• Fix singleUserByIP, does anyone need it? It's been broken since 2.0, maybe longer. There are heavy privacy implications about displaying information about other users connecting from the same IP.
• Remove singleSessionUserByIP, I have no idea what it's supposed to do that the other options don't already do. And it's not implemented.
• We need more unit tests.