[autofit] Add blue-zone support for Tamil script. This essentially moves the Tamil script from the `Indic' hinter to the `Latin' hinter. * src/autofit/afblue.dat: Add blue zone data for Tamil. * src/autofit/afblue.c, src/autofit/afblue.h: Regenerated. * src/autofit/afscript.h: Add Tamli standard character and move data out of AF_CONFIG_OPTION_INDIC block. * src/autofit/afranges.c: Move Tamil data out of AF_CONFIG_OPTION_INDIC block. * src/autofit/afstyles.h: Update Tamil data; in particular, use AF_WRITING_SYSTEM_LATIN.