systemd-python: wrap sd_login_monitor
build-sys: add convinience 'make python-shell'

This will launch $(PYTHON) with $LD_LIBRARY_PATH and $PYTHONPATH
as ./configure-d and DESTDIR-ed. Use as:
   make install DESTDIR=/var/tmp/inst python-shell
Start ctrl-alt-del.target irreversibly

This makes ctrl-alt-del reboots more robust, just like "systemctl
reboot".
audit: since audit is apparently never going to be fixed for containers tell the user what's going on

Let's try to be helpful to the user and give him a hint what he can do
to make nspawn work with normal OS containers.

https://bugzilla.redhat.com/show_bug.cgi?id=893751