o Minor bugfixes (relay shutdown, systemd):
    - Notify systemd of ShutdownWaitLength so it can be set to longer than
      systemd's TimeoutStopSec. In tor's systemd service file, set
      TimeoutSec to 60 seconds, to allow tor some time to shut down.
      Fixes bug 28113; bugfix on 0.2.6.2-alpha.