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/exclude.cpp b/src/exclude.cpp
index 42fb843..264919b 100644
--- a/src/exclude.cpp
+++ b/src/exclude.cpp
@@ -8,6 +8,8 @@
  * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
  */
 
+#include "common.hpp"
+
 #include "exclude.hpp"
 
 namespace ndn