* properly handle .mount unit state tracking when two mount points are stacked one on top of another on the exact same mount point.
Features:
+* improve !/proc/*/loginuid situation: make /proc/*/loginuid less dependent on CONFIG_AUDIT,
+ or use the users cgroup information when /proc/*/loginuid is not available.
* services which create their own subcgroups break cgroup-empty notification (needs to be fixed in the kernel)