TreeView notifications fix (take 2)

[Mike Hearn]

> No, I think IsWindowUnicode is just fine the way it is. The problem
> IMO is that dialog windows are always created first as Unicode, even
> for CreateDialogA. This will need some restructuring of the dialog
> code.

Do you mean they are created as Unicode first in Windows, or in Wine? 

If you mean in Windows, then how do you go about changing the set of a
dialog once it's been created? I'm a bit confused as to exactly what
we're meant to do with the wndproc for a dialog anyway - set it equal to
the dlgproc? I'm not even sure why Windows has two separate fields for
this :(

Are there any docs on exactly how Windows manages the character sets of
dialogs? If it's on MSDN then I've not encountered it in my travels.
Once I understand exactly what has to be done, I'm happy to file a bug
and work on it myself, solving this will resolve a lot of irritating
buglets, mostly involving preferences dialogs in apps like winamp, IE6,
trillian etc.

thanks -mike