Adds initial intermediate qt6 porting state

qt6-after/qt6-migrated-legatus/Z/src/nglapplication/nglsinglecoreapplication.cpp

@@ -0,0 +1,17 @@
+
+
+
+#include "nglsinglecoreapplication.h"
+
+#include "ngl_signal_handler.inc"
+
+
+NGLSingleCoreApplication::NGLSingleCoreApplication(int &argc, char **argv)
+  : QtSingleCoreApplication(argc, argv)
+{
+  
+  signal(SIGTERM, &signalHandler);
+#ifdef Q_OS_WIN
+  installNativeEventFilter(new MyEventFilter);
+#endif
+}