Add PngSuite files and test that uses them. (patch <https://www.blogger.com/blog/post/edit/4095507683943629087/3704088961606316525#> , patch <https://www.blogger.com/blog/post/edit/4095507683943629087/3704088961606316525#> , patch <https://www.blogger.com/blog/post/edit/4095507683943629087/3704088961606316525#> , patch <https://www.blogger.com/blog/post/edit/4095507683943629087/3704088961606316525#> )
Next: Continue pngwriter work
