Add Win32Surface

Hi, SImon!

Hmm, we might as well add Win32Surface, no? :-) BTW, I also added cairo.dll to the list of names to try as this is the default one created by cairo.

Thanks!

Carlos
Did you have a case where `dlopen` failed, and this fixed it? If not please don’t make this change. If so, please make it in a separate commit.