bindings: Manually adding some python bindings

The following features are supported:
- Run basic scenarios using python.
- Iterate over FIB/PIT/CS(nfd) entries

There is a chance that there are memory leaks in the implementation, due
to extensive hacking.

Refs: #2341
diff --git a/model/ndn-common.hpp b/model/ndn-common.hpp
index cbb5f4f..dbb1502 100644
--- a/model/ndn-common.hpp
+++ b/model/ndn-common.hpp
@@ -35,6 +35,9 @@
 
 #include <ndn-cxx/util/time.hpp>
 
+namespace nfd {
+}
+
 namespace ns3 {
 namespace ndn {
 
@@ -60,6 +63,8 @@
 using ::ndn::Block;
 using ::ndn::KeyChain;
 
+namespace nfd = ::nfd;
+
 } // namespace ndn
 } // namespace ns3