[libpng16] Imported from libpng-1.6.8rc01.tar

pngtest.c

@@ -1970,4 +1970,4 @@ main(void)
 #endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_8beta03 Your_png_h_is_not_version_1_6_8beta03;
+typedef png_libpng_version_1_6_8rc01 Your_png_h_is_not_version_1_6_8rc01;