Added some logging to coders/png.c
Added some logging to coders/png.c


Danack/ImageMagick,kwm81/ImageMagick,UniQP/ImageMagick,kwm81/ImageMagick,kwm81/ImageMagick,kwm81/ImageMagick,kwm81/ImageMagick,UniQP/ImageMagick,Danack/ImageMagick,UniQP/ImageMagick,Danack/ImageMagick,UniQP/ImageMagick,Danack/ImageMagick,kwm81/ImageMagick,Danack/ImageMagick,Danack/ImageMagick,UniQP/ImageMagick,UniQP/ImageMagick