SVGHMI: optimization of C part : stop traversing the whole HMI tree, use dual linked list for subscriptions and single linked list for changes from HMI. Intermediate commit, still crashing in some cases.
<?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"/>