This is more flexible; additionally, it would allow character
clusters.
* src/autofit/aftypes.h (SCRIPT, AF_DEFINE_SCRIPT_CLASS): Updated.
(AF_ScriptClassRec): Replace `standard_char[123]' with
`standard_charstring'.
* src/autofit/afscript.h: Replace last three character arguments
of the `SCRIPT' calls with a string parameter, holding the standard
characters (in UTF-8 encoding) separated with spaces.
* src/autofit/afglobal.c, src/autofit/afglobal.h,
src/autofit/afpic.c, src/autofit/afranges.c, src/autofit/hbshim.c
(SCRIPT): Updated.
* src/autofit/afcjk.c (af_cjk_metrics_init_widths),
src/autofit/aflatin.c (af_latin_metrics_init_widths): Updated.