Implement LockWindowUpdate [take 2]

[Mike Hearn]

On Tue, 13 Jan 2004 13:39:48 -0800, Alexandre Julliard wrote:
> Extending the WND structure is OK (though it doesn't seem necessary in
> that case), but accessing it from x11drv is a violation of dll
> separation. We still do that in a number of places but they will have
> to be fixed, so we probably shouldn't add new ones.

Alright. It'd be nice if somebody who knew all the rules of DLL separation
would write them up somewhere. At the moment I basically have to guess.
Apologies if it's already written up or the rules are obvious to all
except me :)

If using WND is not OK, what is the best way to get information from USER
to x11drv then? A wine-specific export that we GetProcAddress() for? Using
SetProp()?