svWidgets TODO:
---------------
- Make all these S3 objects and use methods add, addItem, del, delItem, ...

- In the list of windows (.guiWin), include also RGui windows (console, graphs,
  etc...)

- Make a guiReadPackage() that reads images, icons, menus, toolbars & windows
  in row!

- Allow different styles for images depending on platform and style, and use
  them automatically.

- Internationalize this package

Bugs:
-----
- in winMenuXXX (old stuff, recheck this with current R version):
  1) Error while changing action of a menu
  2) Defining the underline works, but the corresponding shortcut does not
  3) GPF when trying to allocate items to '$Graph1Main'
  4) 'Testit' & $ConsoleMain/Testit' are treated as different things!
