model+helper+ndn-cxx: Adjust ndn::L3Protocol and ndn::StackHelper for NFD 0.4+ model

This commit also restores ndn-cxx Face emulation, which is now necessary
for all NFD's management operations.

Change-Id: Id04cf69a2b0c81972248b6d80055e7c743fa869d
Refs: #3560
diff --git a/wscript b/wscript
index 51ab7f4..734d0f5 100644
--- a/wscript
+++ b/wscript
@@ -139,11 +139,14 @@
     module.source = bld.path.ant_glob(['%s/**/*.cpp' % dir for dir in module_dirs],
                                       excl=[
                                           'apps/*',
-                                          'model/ndn-global-router.cpp',
                                           'model/ndn-app-face.cpp',
                                           'model/ndn-app-link-service.cpp',
-                                          'model/ndn-l3-protocol.cpp',
-                                          'helper/*',
+                                          'helper/ndn-app-helper.cpp',
+                                          'helper/ndn-fib-helper.cpp',
+                                          'helper/ndn-global-routing-helper.cpp',
+                                          'helper/ndn-link-control-helper.cpp',
+                                          'helper/ndn-scenario-helper.cpp',
+                                          'helper/ndn-strategy-choice-helper.cpp',
                                           'utils/topology/*',
                                           'utils/tracers/*',
                                           'model/ip-faces/*']) + ndnCxxSrc + nfdSrc