conversion. The same crash still occures with png/jpeg -> gd -> png/jpeg, because
apparently gd format cannot handle truecolor images.
Turned off debug messages inside gd_gd2.c.
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.