Rename internet-stack to internet, and organize module

examples/error-model/wscript

@@ -1,5 +1,5 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
 
 def build(bld):
-    obj = bld.create_ns3_program('simple-error-model', ['point-to-point', 'internet-stack'])
+    obj = bld.create_ns3_program('simple-error-model', ['point-to-point', 'internet'])
     obj.source = 'simple-error-model.cc'