Fix remaining quantum references to neutron

There was one reference to quantumclient instead of neutronclient in the code
and a few other in doc and comments.

Here's how this bug was uncovered. Next step is figuring out why network creation failed.

```
$ ./bin/sb make -p ../puppet_openstack_builder/data/ -d
1db912fa59be40d1a6a20cd74d0bbdd4
q.create_network({'network': {'name':ci-internal-1db912fa59be40d1a6a20cd74d0bbdd4, 'admin_state_up': True}})['network']
CI subnet 124 doesn't exist. Creating ...
create_subnet({'subnet': { 'name':ci-internal-1db912fa59be40d1a6a20cd74d0bbdd4124,
            'network_id': 9edfb596-7503-463d-b48d-db8761c9f557,
            'ip_version': 4,
            'cidr': '10.2.124.0/24',
            'enable_dhcp': True,
            'gateway_ip': None}})['subnet']

Traceback (most recent call last):
  File "./bin/sb", line 81, in <module>
    main()  
  File "./bin/sb", line 78, in main
    args.func(n, q, k, args)
  File "/home/francois/WORK/dev/scenariobuilder/scenariobuilder/build.py", line 244, in make
    networks[network], index=ci_subnet_index, gateway=gate)
  File "/home/francois/WORK/dev/scenariobuilder/scenariobuilder/build.py", line 99, in make_subnet
    except quantumclient.common.exceptions.QuantumClientException:
NameError: global name 'quantumclient' is not defined
```