Add CFF_CONFIG_OPTION_OLD_ENGINE configuration option.

This controls whether the old FreeType CFF engine gets compiled into
FreeType.  It is now disabled by default.

* devel/ftoption.h, include/freetype/config/ftoption.h
(CFF_CONFIG_OPTION_OLD_ENGINE): New macro.

* src/cff/cffdrivr.c (cff_property_set), src/cff/cffgload.c
(CFF_Operator, cff_argument_counts, cff_builder_add_point,
cff_operator_seac, cff_decoder_parse_charstrings, cff_slot_load),
src/cff/cffgload.h, src/cff/cffobjs.c (cff_driver_init): Use
CFF_CONFIG_OPTION_OLD_ENGINE to guard the affected code.

* docs/CHANGES: Updated.
9 files changed