Allow users to kick people from multicontroller scenarios

[svalencia014]

It would be helpful to remove people who invade scenarios if you did not setup password protection, instead of having to create a new session with a password

[mmp]

Yep, this wouldn't be too hard to add. It probably would make sense to prohibit that IP address from joining that server afterward.

Maybe also we should add a command to set up a password after creating a server.