Support '/org/gnome/SessionManager` Logout
When changing language there's a button that sends
method call time=1571573627.403695 sender=:1.167 -> destination=:1.12 serial=50 path=/org/gnome/SessionManager; interface=org.gnome.SessionManager; member=Logout
which does nothing - likely we're missing something in the shell so gnome-session fails to do anything useful.
see #66 (closed)