dnl dnl Copyright (C) 2011-2015 Peter Breitenlohner dnl dnl This file is free software; the copyright holder dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. dnl dnl -------------------------------------------------------- dnl dnl m4-include this file to define the current libpng version m4_define([libpng_version], [1.6.22])