Convert the virtual-net-device module to the new layout

examples/tunneling/waf

@@ -1 +0,0 @@
-exec "`dirname "$0"`"/../../waf "$@"

src/devices/virtual-net-device/examples/wscript

@@ -1,6 +1,8 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
 
 def build(bld):
+
     obj = bld.create_ns3_program('virtual-net-device', ['point-to-point', 'internet-stack', 'global-routing', 
                                                         'virtual-net-device'])
     obj.source = 'virtual-net-device.cc'
+    

src/devices/virtual-net-device/wscript

@@ -4,11 +4,13 @@
 def build(bld):
     module = bld.create_ns3_module('virtual-net-device', ['node'])
     module.source = [
-        'virtual-net-device.cc',
+        'model/virtual-net-device.cc',
         ]
     headers = bld.new_task_gen('ns3header')
     headers.module = 'virtual-net-device'
     headers.source = [
-        'virtual-net-device.h',
+        'model/virtual-net-device.h',
         ]
 
+    if bld.env['ENABLE_EXAMPLES']:
+        bld.add_subdirs('examples')