[libpng15] Imported from libpng-1.5.15beta07.tar
[libpng15] Bump version to 1.5.15beta08
[libpng15] Avoid a possible memory leak in contrib/gregbook/readpng.c
[libpng15] Made the _SUPPORTED macro definitions consistent.
Merge remote-tracking branch 'origin/libpng15' into libpng15-ssse3