Both the native CFF hinter and the auto-hinter now have a very
similar rendering style.
* include/freetype/freetype.h: Mention that FT_LOAD_TARGET_LIGHT no
longer implies FT_LOAD_FORCE_AUTOHINT.
* include/freetype/ftmodapi.h (FT_MODULE_DRIVER_HINTS_LIGHTLY): New
macro.
* include/freetype/internal/ftobjs.h (FT_DRIVER_HINTS_LIGHTLY): New
macro.
* src/cff/cffdrivr.c (cff_driver_class): Use it.
* src/base/ftobjs.c (FT_Load_Glyph): Update auto-hinter selection
logic.