Add Neutron support

Currently create instance doesnt work in OS installation with Neutron.
To get it work, additional parameter 'nics' should be specified
in Nova 'create' call.
This change allows user to pass 'nics' parameter when create instance.

Syntax to specify '--nic' parameter is same as in novaclient.
--nic <net-id=net-uuid,v4-fixed-ip=ip-addr,port-id=port-uuid>
This parameter can be specified multiple times, to attach multiple
network interfaces to instance.

Closes-Bug: #1257838

Change-Id: I76fb0d99512b1ee70441c924835a900ba0b7acd1
Merge "Add Neutron support"