SVGHMI: widgets are not anymore binary relative or absolute, but have a "relativeness".
Because of allowing multiple variables per widget, we must distinguish if individual variables is relative to page, not the whole widget.
<?xml version='1.0' encoding='utf-8'?>
<SVGHMI xmlns:xsd="http://www.w3.org/2001/XMLSchema" OnWatchdog="echo Watchdog for {name} !" OnStart="xdg-open http://127.0.0.1:{port}/{name}" OnStop="echo Closing {name}" WatchdogInitial="10" WatchdogInterval="5"/>