build: Experimental support to build using precompiled headers

This type of build needs to be explicitly enabled using --with-pch
configure option.

Change-Id: I02dc304187d54c3cf40f1d51b1b11b21f868e225
diff --git a/src/encoding/block.cpp b/src/encoding/block.cpp
index 5656b61..fbd5838 100644
--- a/src/encoding/block.cpp
+++ b/src/encoding/block.cpp
@@ -7,8 +7,10 @@
  * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
  */
 
-#include "encoding/block.hpp"
-#include "encoding/tlv.hpp"
+#include "common.hpp"
+
+#include "block.hpp"
+#include "tlv.hpp"
 
 namespace ndn {