neutron: appliance for IceHouse

Adding a template for creating neutron appliance based
on IceHouse, on top of CentoOS-6.5.
The appliance is configured with ml2 as the core plugin
and ovs (vlan) as the mechanism driver.

Change-Id: Idbda5a4946fcac5a874a5784dfadc8bcadef9f4d
Bug-Url: https://bugzilla.redhat.com/1078862
Signed-off-by: Moti Asayag <masayag@redhat.com>