[gtkada] be aware about window position, size, and maximize status

[Emmanuel Briot]

> I would like to be aware if the user changes the window position or  
> the window size, or if he maximizes the window,
> but I don't find what signals i should connect on

For position, I don't think you'll get a signal for that, this is purely handled
by Windows itself, and does not involve the windows.

For the size, you should connect to the "size_allocate" signal, but it will be
called much more often than just upon user action (for instance it occurs during
the initial size negociation too)

Emmanuel