* QDialog based navigator
* Removed no longer used info area and navigator dock widget
* fixed style sheet
* added some space which can be used to drag navigator when frameless
* callback when frameless is toggled
Status: https://dev.vatsim-germany.org/issues/503#note-10
* 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
* allow to set/unset frameless mode in CDockWidget
* adjusted context menus
* adjusted style sheets
* ini settings for margins
* hidden info area to host floating widgets only visible when floating (allows to CDockInfoArea widgets)
* made some private slots non-virtual