build: Fix compilation on Ubuntu platform and add work-around for ndn-cxx regression

Note that on Ubuntu 12.04, either boost libraries or compiler needs to be upgraded.

Change-Id: I33f1089f961f99abf3d1803bf833e76ff7fb528d
Refs: #2379, #2380, #2382, #2381, #2383
diff --git a/utils/trie/trie.hpp b/utils/trie/trie.hpp
index 28c075e..6d11ecb 100644
--- a/utils/trie/trie.hpp
+++ b/utils/trie/trie.hpp
@@ -152,7 +152,7 @@
                                              // container
     , children_(bucket_traits(buckets_.get(), bucketSize_))
     , payload_(PayloadTraits::empty_payload)
-    , parent_(0)
+    , parent_(nullptr)
   {
   }