BZ #1049633 - Foreman should support VXLAN

https://bugzilla.redhat.com/show_bug.cgi?id=1049633

There are 2 new parameters needed by puppet-neutron for ovs agent/plugin support
for vxlan.  This patch adds those and opens the specified udp port on the
firewall.

Caveats:
This depends on a patch to puppet-neutron that has not yet been accepted, here:
https://review.openstack.org/#/c/55578/

I am not yet sure if we really need to open the firewall ports on all 3 types of node, nor if we need tunneling type in all cases, like where we have agent and plugin on one node (networker)