gdiplus: Add support for extra transformation in GdipMeasureDriverString and GdipDrawDriverString.

[Vincent Povirk]

> Yes, that's a good suggestion, but the tests currently won't pass anyway,
> so adding a test would not prove anything. As I said, the only way to test
> the result at this point is a visual test (which I have here).

It would at least verify and document the correct behavior on windows.