Added ChangedEvent.
diff --git a/Makefile.am b/Makefile.am
index bf0b88a..e048426 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -70,6 +70,7 @@
   ndn-cpp/transport/transport.cpp ndn-cpp/transport/transport.hpp \
   ndn-cpp/c/transport/socket-transport.h ndn-cpp/c/transport/udp-transport.h ndn-cpp/transport/udp-transport.cpp ndn-cpp/transport/udp-transport.hpp \
   ndn-cpp/util/blob.hpp \
+  ndn-cpp/util/changed-event.cpp ndn-cpp/util/changed-event.hpp \
   ndn-cpp/util/dynamic-uchar-vector.cpp ndn-cpp/util/dynamic-uchar-vector.hpp \
   ndn-cpp/util/signed-blob.hpp