The VPNaaS plugin expects the driver to update the connection status
from a separate process/thread/agent.
When the user requests a connection/list, the status is retrived from the VPNaaS DB,
without calling the driver.
To avoid adding a process to actively query and update all connections statuses, this
patch creates a new VPNaaS plugin, to be used instead of hte default one.
This plugin (vmware_nsx_vpnaas) will issue a get-statuses call to the driver,
update the current statuses in the DB, and call the original plugin.
Change-Id: Ib750bfb8f0c8ad12265fa71506182ff5d7e8030a
e3f103f269