Upstream 463c3bd09b
Notice: this fix don't manage monochrome/monovisual values
but just fix the security issue CVE-2014-2497
failing when trying to load such an image
This initial checkin has no changes to any of the libgd code so it can
be used as a basis for diffs. It also will not build currently because
of this. The PHP gd checks need to be incorporated along with a bit of
other config magic. It also shouldn't break the build and will only
take effect if you use --with-gd=php right now.