64bit Windows support (patch by Michael Menegakis)

code/jpeg-6b/jmorecfg.h

@@ -158,9 +158,11 @@ typedef short INT16;
 /* INT32 must hold at least signed 32-bit values. */
 
 /* MinGW basetsd.h defines INT32 - don't redefine it */
+#ifndef __WIN64
 #if !(defined __MINGW32__ && defined _BASETSD_H)
 typedef long INT32;
 #endif
+#endif
 
 /* Datatype used for image dimensions.  The JPEG standard only supports
  * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore