[autofit] Add support for Georgian Mtavruli characters. This will be part of the forthcoming Unicode 11.0. * src/autofit/afblue.dat: Add blue zone data for Mtavruli. * src/autofit/afblue.c, src/autofit/afblue.h: Regenerated. * src/autofit/afscript.h: Add Mtavruli standard character.