[ros-kernel] Locking changes

[Ge van Geldorp]

> Log message:
> 	[Sorry for too many changes in one patch, but it's 
> nearly impossible to separate it without breaking the functionality]

I think this is the patch that causes problems for me.
When using the VMware display driver and building with DBG := 1 ReactOS
crashes when switching to graphics mode. The problem is that the screen
surface is locked in objects/brush.c function IntPatBlt() and then, via
IntEngBitBlt() the DrvBitBlt() function is called. The DrvBitBlt()
function in the VMware drive calls EngLockSurface() on the screen
surface too, which will try to acquire a fast mutex for the second time.
With DBG := 1 this will cause an assert.

Gé van Geldorp.