Favor: review refactor of gdi32/freetype.c - AddFontToList

[Jeremy White]

So in my ongoing quest to get CreateScalableFontResource completed, I
believe that I need to refactor gdi32/freetype.c - AddFontToList to
expose an interface to allow me to retrieve a Face *.

Attached is a series of 4 patches that accomplish what I believe to be a
reasonable refactoring of that function.
> From my analysis, the only material change in the logic flow is that the
> old code would skip a face that existed prior to building the new Face *
> structure. The new code goes ahead and builds up a proposed Face *
> before testing to see if the proposed new Face should be skipped.

It passes the font tests and notepad still runs, but I recognize that
this is a much more invasive change than I am really qualified to make.

I would appreciate others with expertise in this area reviewing this
series.  Also, if there is advice on a standard bevy of tests I could
run, I would appreciate it.  There is a fair amount of special case
logic in this function, and I know that our regression tests do not
exercise it all.

Thanks,

Jeremy