Add setup.d to umount -l /afs

Lazily umount /afs inside the chroot, before attempting the
normal umount.  gvfs can leave something hanging around such that
a normal umount returns EBUSY.  (Trac: #1500)
Add reactivate-helper to query logind

- Add a "reactivate-helper" script, and use it in the session
  teardown to determine whether or not we should reactivate.
Release 2.0.47

Release 2.0.47, containing the fixes for Trac: #1497, #1499
and #1500