Use uBridge for VirtualBox connections plus some cleaning. Ref #267.

gns3server/handlers/api/compute/vpcs_handler.py

@@ -201,7 +201,7 @@ class VPCSHandler:
         nio_type = request.json["type"]
         if nio_type not in ("nio_udp", "nio_tap"):
             raise HTTPConflict(text="NIO of type {} is not supported".format(nio_type))
-        nio = vpcs_manager.create_nio(vm.vpcs_path, request.json)
+        nio = vpcs_manager.create_nio(request.json)
         yield from vm.port_add_nio_binding(int(request.match_info["port_number"]), nio)
         response.set_status(201)
         response.json(nio)