[libpng16] fix: Update the cICP implementation yet more
For the sake of completeness:
* Add the cICP entry to the list of known chunks to ignore inside
`png_set_keep_unknown_chunks`.
* Handle cICP in `png_read_end`, alongside cHRM, gAMA, iCCP, sRGB.
* In pngtest.c, move the cICP test code near cHRM, gaMA, iCCP, sRGB.
This is a cherry-pick of commit 27c2ac722fd99b8622cead655034208ce96346ac
from branch 'libpng18'.
Reviewed-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
3 files changed
