[LightDM] Using LightDM as a lockscreen

[Sean Davis]

Good day everyone,

I'm working with the Xubuntu team on using LightDM as a lock screen.  
Currently, we're trying to use `gdmflexiserver` to send us back to the 
user switcher.  However, it always spawns lightdm into tty9 and you can 
easily return to your session unlocked in tty7.

Is there a reliable method to fully lock your computer with lightdm?

Thanks,
Sean