Remove application; it's now part of the settings app

Signed-off-by: Simon Busch <morphis@gravedo.de>
Implement the other part of the system update

* running the update will reboot the device into the system update mode (see
  http://freedesktop.org/wiki/Software/systemd/SystemUpdates/)
* in system update mode the run-update.sh script is executed through the systemd service
  and updates all previously downloaded packages

Signed-off-by: Simon Busch <morphis@gravedo.de>