Correctly work with systemd/logind

[1wilkens]

Currently the session started by rdm is partly recognized by loginctl (no seat or tty attribute present) and all authentication attempts (for example shutdown/reboot) fail with Failed to power off system via logind: Interactive authentication required..
This indicates that the pam_systemd.so module is not properly executed for the session (although the runtime directory in /var/run/user/ is created..) which might be caused by a problem in the pam configuration file.

More research is needed to determine which practices we need to follow.

As proper systemd support is one of the core principles rdm is built on, this is a blocker for v0.1!

[1wilkens]

This might also be related to the way pam is used. Most DMs seems to first open a session without authentication when showing the ui (with XDG_SESSION_CLASS set to greeter) and then launching the "real" session upon login.

Research should determine the reason for this behaviour and next steps for rdm.