How to allow FORWARDing with firewalld on a Fedora 19 router
Finally, I found the answer ...
# cat /etc/firewalld/direct.xml
<?xml version="1.0" encoding="utf-8"?>
<direct>
[ <rule ipv="ipv4" table="filter" chain="FORWARD_direct" priority="0"> -i eth0 -o eth1 -j ACCEPT </rule> ]
</direct>
This feature appeared in firewalld-0.3.4-1.fc19 but there is no firewall-cmd support yet, and the man page was omitted, but it WORKS
Eventually found it in the following mailing list http://www.spinics.net/linux/fedora/fedora-security/msg01688.html