[devel] Mention zlib-libpng license in each source file
diff --git a/scripts/makefile.vcwin32 b/scripts/makefile.vcwin32
index ab7541a..9fb7cae 100644
--- a/scripts/makefile.vcwin32
+++ b/scripts/makefile.vcwin32
@@ -1,7 +1,10 @@
# makefile for libpng
# Copyright (C) 1998 Tim Wegner
# Copyright (C) 2006,2009 Glenn Randers-Pehrson
+#
+# This code is released under the zlib-libpng license.
# For conditions of distribution and use, see copyright notice in png.h
+#
# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
# To use, do "nmake /f scripts\makefile.vcwin32"