See
http://typedrawers.com/discussion/470/new-microsoft-size-specific-design-selection-mechanism
for the announcement.
* include/freetype/tttables.h (TT_OS2): Add fields
`usLowerPointSize' and `usUpperPointSize'. Since FreeType returns
this structure only as a pointer through `FT_Get_Sfnt_Table', there
shouldn't be any ABI problems.
* src/sfnt/ttload.c (tt_face_load_os2): Implement it.
* docs/CHANGES: Updated.