use __stdcall for mingw gcc
use __stdcall for mingw gcc


bcampbell/DevIL,DentonW/DevIL,DentonW/DevIL,Agadoul/DevIL,DentonW/DevIL,DentonW/DevIL,bcampbell/DevIL,DentonW/DevIL,DentonW/DevIL,bcampbell/DevIL,Agadoul/DevIL,Agadoul/DevIL,Agadoul/DevIL,Agadoul/DevIL,bcampbell/DevIL,Agadoul/DevIL,bcampbell/DevIL,bcampbell/DevIL