WINED3D / D3D9: SetVertexShader & SetPixelShader should not change the shader's refcount

[H. Verbeet]

> The best thing to do is add an internal reference instead of referencing the parent. e.g.
> if (pShader != NULL) {
>     IWineD3DVertexShader_AddRef(pShader);
> }
> if (oldShader != NULL) {
>     IWineD3DVertexShader_Release(oldShader);
> }
Is that reference really needed?