[graph] Complete removal of legacy blitter.
This switches the remaing monochrome rendering of headers to the main blender and deletes the legacy blitter. The old blitter can handle exotic target surfaces like monochrome or 4-bit bitmaps. Anything beyond the alpha blender can do.
- graph/grfont.c (grWriteCellChar, grWriteCellString): Switch from
grBlitGlyphToBitmap
togrBlitGlyphToSurface
. - graph/grblit.[ch]: Delete files.
- graph/graph.h, graph/grconfig.h: Remove references.
- graph/rules.mk, graph/meson.build, vms_make.com, builds/windows/msvc/migs.vcxproj: Update build scripts.