Trying to get rid of gdi.h

[Rémi Assailly]

Hi all !

This mail is a resent because I noticed that it does not appear in 
wine-devel...

I started a work to get rid of GDI_GetObjPtr and GDI_ReleaseObj in 
x11drv but I am not sure if have chosen a good way.
This patch is incomplete : some GDI_* are still staying, those that 
cannot be removed using my way.

Working on it I noticed something which can be interesting : graphics 
are faster because some times GDI_GetObjPtr were called twice and in my 
patch only once.

I would some comments on this work.

Rémi