core: Basic implementation of Scheduler

refs #1119 (http://redmine.named-data.net/issues/1119)

Change-Id: I1783857452941794a2538534d3492d30ac58dd25
diff --git a/daemon/common.hpp b/daemon/common.hpp
index d87a067..9b50fda 100644
--- a/daemon/common.hpp
+++ b/daemon/common.hpp
@@ -17,9 +17,12 @@
 #include <boost/function.hpp>
 #include <boost/bind.hpp>
 #include <boost/ref.hpp>
+#include <boost/asio.hpp>
+#include <boost/assert.hpp>
 
 #include <vector>
 #include <list>
+#include <set>
 
 namespace ndn {