wined3d [3]: Add IsImplicit/SetImplicit surface functions.

[Markus Amsler]

Stefan Dösinger wrote:
> Does wined3d have to know if the surface is implicit? Wouldn't it be 
> sufficient to just store it in the d3d8/9 surface? This would avoid adding 
> more complexity to wined3d.
The problem is the implicit surface (IS) destruction in wined3d (device 
and swapchain). Release won't destroy them, so wined3d needs a way to 
destroy IS. I solved it with setImplicit(false); release;.

Another posibility would be to move the IS destruction to d3d8/d3d9. 
There we would have more control over the IS, and the parentDevice 
problem from patch [5] would also be solved. But it means some code 
duplication in d3d8/d3d9.

I went for less code.