VPNInterfaces collection holds list of all VPNInterface
objects currently available for wodVPN. This is list of all installed
virtual network adapters that can be used to route traffic to remote
peer.
Currently wodVPN supports included 'WeOnlyDo Network Adapter', but it
can also use Wippien's adapter, and
OpenVPN's adapter. Only one process at
a time can use one adapter, but multiple instances of wodVPN in same
process (inside your application) can all share same adapter.
