[libpng16] Imported from libpng-1.6.16rc01.tar
[libpng16] Imported from libpng-1.6.16rc02.tar
Fix an overflow in png_combine_row with very wide interlaced images

Signed-off-by: John Bowler <jbowler@acm.org>
Merge branch 'libpng16' of /home/jbowler/src/libpng/libpng into libpng16
[libpng16] Fixed an overflow in png_combine_row with very wide interlaced

images.
[libpng16] Imported from libpng-1.6.16rc03.tar
Merge branch 'libpng16' of /home/jbowler/src/libpng/libpng into libpng16