[autofit] Add support for Arabic script. Thanks to Titus Nemeth <tn@tntypography.eu> for guidance! * src/autofit/afblue.dat: Add blue zone data for Arabic. * src/autofit/afblue.c, src/autofit/afblue.h: Regenerated. * src/autofit/afscript.h: Add Arabic standard characters. * src/autofit/afranges.c: Add Arabic data. * src/autofit/afstyles.h: Add Arabic data. * docs/CHANGES: Document it.