On Windows the GTK+ stack does not hard depend on PangoFT2 (thus
Fontconfig--GTK+ uses PangoWin32 to do the Font discovery and
configuration stuff by default, unless one uses an envvar to force
PangoFT2 usage), unlike *NIX platforms, so we need to check for
it by doing:

-On Windows, enable the test code that uses PangoFT2/FontConfig if
 PangoFT2 and FontConfig is found during configure.  On Visual Studio
 builds, this is set to be disabled in config.h.win32(.in), and can be
 manually enabled by uncommenting #define HAVE_PANGOFT2 1 in
 config.h.win32 prior to the build (or rebuild).  This continues to have
 FontConfig and PangoFT2 to act as an optional dependency.

-On non-Windows platforms, make PangoFT2 and FontConfig a hard dependency,
 which is what the current code assumes.

We might probably need to make the custom TTF load via PangoWin32 and/or
the native Windows API to run the tests when PangoFT2 and FontConfig are
not found on Windows.

Also bump ...