1) Allow the creation of network types outside the norm of vxlan/vlan.
2) tempest_public_physical_net_type was used in the resources setup
tasks, while it was defined in defaults as
tempest_public_net_physical_type.
3) Consolidate the public network setup task from "if flat" and "if
vlan" into something that will accommodate other network types
such as local.
4) Do not require a segmentation id on private network setup,
enabling the use of types other than vxlan/vlan.
Change-Id: I54de9862686f9c67266d4c7335f00c0553202c85
403fcf8e19