Adding FreeType Library Support to Bitmap Drivers

N.B. this FreeType approach is officially deprecated because of its inherent font-selection issues (fonts must be specified by filename) and because it only supports left-to-right layout (i.e., there is no support for complex text layout languages). Specialized libraries or system services that automatically find the best system font to render the given (unicode) glyph and which support complex text layout should be used instead. Those possibilities include Qt (available on all platforms and used by our qt device driver), the pango/cairo subset of the GTK+ suite of libraries (available on all platforms and used directly by our cairo device driver and indirectly by our psttf device driver), Uniscribe (available only on Windows for Windows 2000 and later), and DirectWrite (available only on Windows for Windows 7 and later). Currently the wingcc and gd device drivers are the only ones that depend on the FreeType approach described here. Because of the limitations of this approach we have plans to update wingcc to use either Uniscribe or DirectWrite, and once those plans are realized we will likely retire the gd device driver (currently deprecated because of the limitations of the current approach) and also retire this Freetype approach.