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/util/time.hpp b/src/util/time.hpp
index 8f110a9..82d59e9 100644
--- a/src/util/time.hpp
+++ b/src/util/time.hpp
@@ -8,7 +8,7 @@
 #ifndef NDN_TIME_HPP
 #define NDN_TIME_HPP
 
-#include "common.hpp"
+#include "../common.hpp"
 #include <boost/date_time/posix_time/posix_time.hpp>
 
 namespace ndn {