model+apps+utils+examples+ci+docs: Update code for changes in ns-2.23

- Replace removed RandomVariable with RandomVariableStream
- Replace deprecated usages of AddTraceSource
- Update changed LogComponent interface

ci: This commit also integrates a script for Jenkins and Travis CI to
clone NS-3 and pybindgen repositories, so the code can be built.

docs: Update to reflect new home of ndnSIM and related sources

Change-Id: Ic14e1269bf15366b0041fd670c577053b6704dc7
Refs: #3122, #3123
diff --git a/apps/ndn-app.hpp b/apps/ndn-app.hpp
index 7d335b3..8ba90d3 100644
--- a/apps/ndn-app.hpp
+++ b/apps/ndn-app.hpp
@@ -80,6 +80,10 @@
   virtual void
   OnData(shared_ptr<const Data> data);
 
+public:
+  typedef void (*InterestTraceCallback)(shared_ptr<const Interest>, Ptr<App>, shared_ptr<Face>);
+  typedef void (*DataTraceCallback)(shared_ptr<const Data>, Ptr<App>, shared_ptr<Face>);
+
 protected:
   /**
    * @brief Do cleanup when application is destroyed