refs #312, Navigator (aka navigation bars)

* different dyn. property names for main window, dock window and infoarea
* dyn.properties for nested QWidgets
* style sheet for navigator
* utility function to delete layout
* added standard OS icons, some formatting in CICons
* actions in main window to be used in navigator
* main window becomes normal window when minimized so it is correctly displayed in Win taskbar

Remark: Frameless floating dockwidgets with rounded borders not yet working

src/blackgui/stylesheetutility.cpp

@@ -244,6 +244,12 @@ namespace BlackGui
         return f;
     }
 
+    const QString &CStyleSheetUtility::fileNameNavigator()
+    {
+        static const QString f("navigator.qss");
+        return f;
+    }
+
     const QString &CStyleSheetUtility::fileNameDockWidgetTab()
     {
         static const QString f("dockwidgettab.qss");