GlobalActions: Put device to sleep when power off selected.

* Something is screwy on this hardware and causes the device to freeze during
  the ShutdownThread. Lets put the device to sleep to attempt to imitate the
  IR power button functionality.

* Some more work will need to be done to this to fully imitate the function,
      but it is a start.

Signed-off-by: Brandon McAnsh <brandonm@matricom.net>