Moving OpenStack networks definitions to barclamp-neutron

This is pull request for moving OpenStack Nova networks to barclamp-neutron.
This change will:
- simplify network configuration
- gives better flexibility for user deployments.

Warning!!! Please don't merge this until it will be tested

Depends on:
    crowbar/crowbar#2071


Is this still available under `node.crowbar["crowbar"]`? I'd think you'd want to look at the neutron attributes.