include: Add IAutomaticUpdates, IUpdateSession, IUpdateSearcher, IUpdateDownloader and IUpdateInstaller interfaces.

This confuses applications like Steam, which hook d3d9 and opengl
functions. It sees that the application uses opengl32, but it doesn't
realize that d3d9 is wrapped to opengl. Thus it starts messing around
with wined3d's wgl context. It usually tries to draw geometry with the
context, but cannot deal with some of the obscure extensions we have
activated.

Otherwise it will be 0 if GL_ARB_multitexture is not available.