Restore brightness level earlier in startup

Load the brightness module earlier in the shell startup process
in order to restore the brightness level before any other screen
shows up, ie., the intro screen.

Signed-off-by: Martin Abente Lahaye <tch@sugarlabs.org>

src/jarabe/main.py

@@ -71,6 +71,7 @@
 from jarabe.view.service import UIService
 from jarabe import apisocket
 from jarabe import testrunner
+from jarabe.model import brightness
 
 
 _metacity_process = None
@@ -402,6 +403,7 @@ def main():
     GLib.idle_add(setup_cursortracker_cb)
     sound.restore()
     keyboard.setup()
+    brightness.get_instance()
 
     sys.path.append(config.ext_path)