Preview is now 90% done.
- Graphic menus to be included int preview.
- Deleted unneeded icons.
- Now you can edit the name of the menu component.

* Separator.cs: Forgot to mark TagName as public.
* add.png: Deleted.
* help.png: Deleted.
* edit.png: Deleted.
* check.png: Deleted.
* folder.png: Deleted.
* settings.png: Deleted.
* RAppMenu.csproj: Removed above elements.
* MainWindow.cs: Now you can edit the name of the menu components.
* PreviewWindow.cs: Now it recursively allows submenus.
* SeparatorTreeNode.cs: No invented name, get Separator.TagName.