I've found the way to view the SSH/Telnet Console, but how do I define and access accounts? The File > FTP/Telnet > SSH/Telnet Account Manager menu selection is grayed out. Is this feature implemented?
It is implemented. It seems to be greyed out when you are connected to a SSH/Telnet console. When you disconnect from all terminals (tabs on the console) the menu item File > FTP/Telnet > SSH/Telnet Account Manager is active again. At least that's how it works for me in UE13.20+2.
In the console itself you should also be able to open the manager via the "Accounts" button when not connected.