Ignore "#" delimited comments in input file to pnm2png.c.

trusting the CMF bytes in the PNG datastream.

png_create_write_struct() (Andrew Church).

handling in libpng.1.5.x and with bugs in libpng-1.4.x and earlier.

about the need to call png_set_keep_unknown_chunks() when writing them.

Rebuilt the configure scripts.

'off'.  Previously the ARM NEON specific files were still built if the option
was switched 'off' as opposed to being explicitly disabled.

switched 'off'.  Previously the ARM NEON specific files were still built
if the option was switched 'off' as opposed to being explicitly disabled.

can handle.

Reverted previous attempt to allow gAMA and sRGB non-support with the
simplified API.

png_image_write_main() in pngwrite.c (bug report from Yuriy Levchenko).

chunk length written by libpng-1.6.0 and 1.6.1.