[GRASS-git] [OSGeo/grass] 8efd22: configure: Support for libpng-config (#2679)

[Huidae Cho]

  Branch: refs/heads/main
  Home:   https://github.com/OSGeo/grass
  Commit: 8efd2289380ab29786c757bc2a587dca1ca69a14
      https://github.com/OSGeo/grass/commit/8efd2289380ab29786c757bc2a587dca1ca69a14
  Author: Huidae Cho <grass4u at gmail.com>
  Date:   2022-12-06 (Tue, 06 Dec 2022)

  Changed paths:
    M .github/workflows/build_centos.sh
    M configure
    M configure.ac
    M mswindows/osgeo4w/gdal-config
    A mswindows/osgeo4w/libpng-config

  Log Message:
  -----------
  configure: Support for libpng-config (#2679)

* configure: PNGVER environment variable to pickup libpng16.dll from OSGeo4W v2

* Add libpng-config (part of libpng) support and missing script for OSGeo4W

* Add --dll-version to libpng-config; Update gdal-config to detect libpng version

* Add --libpng-config to build_centos.sh

* Fix for clang (no implicit declaration of function)

* Use libpng-config --ldflags instead of --libs to include -L flags

* Let's try LDFLAGS for Ubuntu 20.04

* Define HAVE_PNG_H

* Consistent comments

* Delete trailing spaces; Replace tabs+spaces+tabs with tabs+spaces

* Copyright year to 2022

* Revert build_ubuntu-20.04.sh

* Add --static flag to libpng-config to include -lm -lz

Co-authored-by: Huidae Cho <grass4u at gmail.com>