FT_FACE_FLAG_TRICKY to indicate that the font format's hinting
engine is necessary for correct rendering.
At the same time, slightly modify the behaviour of tricky fonts:
FT_LOAD_NO_HINTING is now ignored. To really force raw loading
of tricky fonts (without hinting), both FT_LOAD_NO_HINTING and
FT_LOAD_NO_AUTOHINT must be used.
Finally, tricky TrueType fonts always use the bytecode interpreter
even if the patented code is used.
* include/freetype/freetype.h (FT_FACE_FLAG_TRICKY, FT_IS_TRICKY):
New macros.
* src/truetype/ttdriver.c (Load_Glyph): Handle new load flags
semantics as described above.
* src/truetype/ttobjs.c (tt_check_trickyness): New function, using
code of ...
(tt_face_init): This function, now simplified and updated to new
semantics.
* src/base/ftobjs.c (FT_Load_Glyph): Don't use autohinter for tricky
fonts.
* docs/CHANGES: Document it.
