[autofit] Add support for Thai script. Thanks to Ben Mitchell <ben@rosettatype.com> for guidance with blue zone characters! * src/autofit/afblue.dat: Add blue zone data for Thai. * src/autofit/afblue.c, src/autofit/afblue.h: Regenerated. * src/autofit/afscript.h: Add Thai standard characters. * src/autofit/afranges.c: Add Thai data. * src/autofit/afstyles.h: Add Thai data.