WindowManager: fix default state when luna-next starts

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>
Launcher: Improve the layout of the launcher bar

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>
Dashboard: Use the slidingArea widget for the notifications

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>