* include/freetype/config/ftheader.h: removed obsolete macros like
FT_SOURCE_FILE, etc.. and added cache-specific macro definitions that
were previously defined in <freetype/ftcache.h>. Added comments to be
included in a new API Reference section.
* src/*/*: removed the use of FT_SOURCE_FILE, etc.. now, each component
needs to added its own directory to the include path at compile time.
Modified all "rules.mk" and "descrip.mms" accordingly..
* *.mk: Implemented `platform' target to disable auto-detection.
Added support for clipped direct rendering in the smooth renderer.
This should not break binary compatibility of existing applications.
* include/freetype/fttypes.h, include/freetype/ftimage.h: Move
definition of the FT_BBox structure from the former to the latter.
* include/freetype/ftimage.h: Add `ft_raster_flag_clip' value to
FT_Raster_Flag enumeration.
Add `clip_box' element to FT_Raster_Params structure.
* src/smooth/ftgrays.c (grays_convert_glyph): Implement it.
* src/raster/ftraster.c (ft_black_render): Test for unsupported
direct rendering before testing arguments.