New function. Guesstimate what Unicode subranges a font covers based on

New function. Guesstimate what Unicode subranges a font covers based on

1999-12-06  Tor Lillqvist  <tml@iki.fi>

* gdk/win32/gdkfont-win32.c (check_unicode_subranges): New
function. Guesstimate what Unicode subranges a font covers based
on the codepages. Windows tells us it covers. This will hopefully
help those Windows versions or fonts that don't give us any useful
Unicode subrange information with GetTextCharsetInfo. Call this
function in gdk_font_load_internal.

* gdk/win32/{gdkdnd,gdkimage,gdkpixmap,gdkprivate}-win32.c: Misc
minor changes.