build+src: Updating common.hpp to import (std|boost)::(shared_ptr|function|...) into ndn namespace

Also fixing a small bug in wscript.

Change-Id: I8f20caa177cc015b7433d1ecd3db385f533437c6
diff --git a/src/encoding/buffer.hpp b/src/encoding/buffer.hpp
index f6b7a17..1dc8f7e 100644
--- a/src/encoding/buffer.hpp
+++ b/src/encoding/buffer.hpp
@@ -10,7 +10,7 @@
 #ifndef NDN_BUFFER_HPP
 #define NDN_BUFFER_HPP
 
-#include "common.hpp"
+#include "../common.hpp"
 
 #include <boost/iostreams/detail/ios.hpp>
 #include <boost/iostreams/categories.hpp>