[sfnt] Implement support for `OS/2' table version 5.

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.
4 files changed