removing compiler warnings (Visual C++ /W4)
* Jamfile, src/otvalid/{otvcommn.h,otvgdef.c,otvgpos.c,otvgsub.c,
otvjstf.c}: modified the code to use a different pre-processor trick
to implement the OTV_NEST1, OTV_NEST2 and OTV_NEST3 macros. The code
now compiles neatly with Visual C++. The 'otvalid' module has been
put in the Jamfile build again.
(unfinished) `otlayout' module but has been heavily modified to make
it much more compact.
* src/otvalid/*: New module.
* include/freetype/ftotval.h, src/base/ftotval.c,
include/freetype/internal/services/svotval.h: New files.
* include/freetype/config/ftmodule.h: Add otv_module_class.
* include/freetype/config/ftheader.h (FT_OPENTYPE_VALIDATE_H): New
macro.
* include/freetype/internal/ftserv.h
(FT_SERVICE_OPENTYPE_VALIDATE_H): New macro.
* include/freetype/internal/fttrace.h (otvmodule, otvcommon,
otvbase, otvgdef, otvgpos, otvgsub, otvjstf): New trace components.
* include/freetype/ftchapters.h: Updated.
* src/base/Jamfile (Library), src/base/descrip.mms (OBJS),
src/base/rules.mk (BASE_EXT_SRC): Updated.
* docs/CHANGES: Updated.
David Turner