rebrand Nicira NVP to VMware NSX

- rename directory neutron_plugin_nicira to neutron_plugin_vmware
- rename puppet classes, manifests, types
- rename directories to reflect class name change
- change configuration file name and path
- rename neutron plugin
- rename neutron configuration file settings

Blueprint: https://blueprints.launchpad.net/neutron/+spec/nicira-plugin-renaming
Bug: https://bugs.launchpad.net/ubuntu/+source/neutron/+bug/1273877