Set nova's default_floating_pool setting.

Without this the floating-ip extension looks for a neutron network
called 'nova' to handle floating IP requests.

Change-Id: If04bb47b2d2df4e87d0dd724c4598b94f5c97872
Fixes-Bug: #1239450
Switch to using refresh-env.

This is a clarification of intent we're doing in the incubator.

Change-Id: I94dc5d5721d7915a608851b9a56bf4db28d96acf
Remove obsolete docs about iptables.

They aren't part of this script for some time.

Change-Id: I3fd86d81d9e815fb294682585e7a0a59c98533be
Document tripleo-cd configuration.

Change-Id: I87465060a57a7468834ac9228e248af90bac709f
Support working with neutron host-routes.

If there is a neutron host-route for metadata, we shouldn't try to
replace the metadata route - instead just change the default route.

Change-Id: I27ab5057b32fcab00e4465913f03336125cbd665
Use kvm for the cd-overcloud.

It defaults to qemu in devtest_overcloud, and we definitely don't want
qemu in prod.

Change-Id: Ic14a556daa26efabdf0a101e3cc2047f74be56ec