- using FT_UNUSED instead of UNUSED
- using FT_LONG64 and FT_INT64 instead of LONG64 & INT64
- using FT_SIZEOF_INT & FT_SIZEOF_LONG instead of...

- removed the #ifdefs that used SIZEOF_INT, instead we now
  use FT_Int32 and FT_UInt32 when needed to support
  32-bits quantity correctly on 64-bits systems..