WIP: Make coe::nexus work with Havana

The coe::nexus class was still referring to OpenStack
Networking as Quantum.  Since the name was changed to
Neutron in Havana, we need to follow suit.  This patch
changes all references from Quantum to Neutron.

Additionally, the configuration files for the Cisco plugins
have changed in Havana.  This patch provides a new template
and appropriate logic to populate it.

Partial-Bug: #1276168

Note to reviewers: 
This is WIP.  There is likely a patch to puppet-neutron needed to clean up some stale-but-harmless config as well, and a corresponding patch to puppet_openstack_builder too.  In the interim you can try this out by doing the following:

In /etc/puppet/data/global_hiera_params/common.yaml, set:
```
tenant_network_type: vlan
```

In /etc/puppet/data/hiera_data/user.common.yaml add something like (yes, there's still some redundant info in there as of right now):
```
neutron::core_plugin: 'neutron.plugins.cisco.network_plugin.PluginV2'
neutron::plugins::cisco::nexus_plugin: 'neutron.plugins.cisco.nexus.cisco_nexus_plugin_v2.NexusPlugin'
neutron::plugins::cisco::vswitch_plugin: 'neutron.plugins.openvswitch.ovs_neutron_plugin.OVSNeutronPluginV2'
neutron::plugins::ovs::network_vlan_ranges: 'physnet1:500:600'
neutron::agents::ovs::bridge_uplinks:
  - 'br-eth1:eth1'
neutron::agents::ovs::bridge_mappings:
  - 'physnet1:br-eth1'
coe::nexus::nexus_credentials:
  - '192.168.2.81/admin/password'
  - '192.168.2.82/admin/password'
coe::nexus::nexus_config:
  'switch1':
    'ip_address': '192.168.2.81'
    'username': 'admin'
    'password': 'password'
    'ssh_port': 22
    'servers':
      'server1': '1/1'
      'server2': '1/2'
  'switch2':
    'ip_address': '192.168.2.82'
    'username': 'admin'
    'password': 'password'
    'ssh_port': 22
    'servers':
      'server3': '1/3'
```