webapplication: implement application relaunch

Signed-off-by: Simon Busch <morphis@gravedo.de>
Export headless property for the web application

Signed-off-by: Simon Busch <morphis@gravedo.de>
Rework application/window relation to support more than one window per app

Signed-off-by: Simon Busch <morphis@gravedo.de>
Use maliit as input management module

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