Mova nova net config to lib/nova

* Moves Nova network configuration settings out of stack.sh into lib/nova
* Rename NET_MAN to NETOWRK_MANAGER to match nova.conf attribute name

Change-Id: I9bd2955def553499aa832eda1f0959afe494206a
Merge branch 'run-service' into dt-test
Merge branch 'nova-init-net' into dt-test