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.h

@@ -71,6 +71,9 @@ namespace BlackGui
         //! File name infobar.qss
         static const QString &fileNameInfoBar();
 
+        //! File name navigator.qss
+        static const QString &fileNameNavigator();
+
         //! File name dockwidgettab.qss
         static const QString &fileNameDockWidgetTab();