hg: jdk9/client/jdk: 8167228: Update to libpng 1.6.28

[philip.race at oracle.com]

Changeset: 87b36fe054e1
Author:    prr
Date:      2017-01-23 11:59 -0800
URL:       http://hg.openjdk.java.net/jdk9/client/jdk/rev/87b36fe054e1

8167228: Update to libpng 1.6.28
Reviewed-by: serb, azvegint

! src/java.desktop/share/native/libsplashscreen/libpng/CHANGES
! src/java.desktop/share/native/libsplashscreen/libpng/LICENSE
! src/java.desktop/share/native/libsplashscreen/libpng/README
! src/java.desktop/share/native/libsplashscreen/libpng/png.c
! src/java.desktop/share/native/libsplashscreen/libpng/png.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngconf.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngerror.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngget.c
! src/java.desktop/share/native/libsplashscreen/libpng/pnglibconf.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngmem.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngpread.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngpriv.h
! src/java.desktop/share/native/libsplashscreen/libpng/pngread.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngrio.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngrtran.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngrutil.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngset.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngstruct.h
- src/java.desktop/share/native/libsplashscreen/libpng/pngtest.c
! src/java.desktop/share/native/libsplashscreen/libpng/pngtrans.c
- src/java.desktop/share/native/libsplashscreen/libpng/pngwio.c
- src/java.desktop/share/native/libsplashscreen/libpng/pngwrite.c
- src/java.desktop/share/native/libsplashscreen/libpng/pngwtran.c
- src/java.desktop/share/native/libsplashscreen/libpng/pngwutil.c