[ftvalid] Introduce FT_THROW() in FT_INVALID_XXX macros.

Original patch is designed by Werner Lemberg.  Extra part
for otvalid and gxvalid are added by suzuki toshiya, see
discussion:
http://lists.nongnu.org/archive/html/freetype-devel/2014-12/msg00002.html
http://lists.nongnu.org/archive/html/freetype-devel/2014-12/msg00007.html

* include/internal/ftvalid.h: Introduce FT_THROW() in FT_INVALID_().
* src/gxvalid/gxvcommn.h: Ditto.
* src/otvalid/otvcommn.h: Ditto.
4 files changed