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-consumer-cbr.hpp b/apps/ndn-consumer-cbr.hpp
index 6e8f6c1..fbf606c 100644
--- a/apps/ndn-consumer-cbr.hpp
+++ b/apps/ndn-consumer-cbr.hpp
@@ -68,7 +68,7 @@
 protected:
   double m_frequency; // Frequency of interest packets (in hertz)
   bool m_firstTime;
-  RandomVariable* m_random;
+  Ptr<RandomVariableStream> m_random;
   std::string m_randomType;
 };