mgmt: mark StatusDatasetContext as noncopyable

This commit also changes function-by-value to function-by-const-reference
in Dispatcher.

refs #2107

Change-Id: If7859579ea9cdd953476642c05104355acdf1620
diff --git a/src/mgmt/dispatcher.cpp b/src/mgmt/dispatcher.cpp
index b43334b..78217a9 100644
--- a/src/mgmt/dispatcher.cpp
+++ b/src/mgmt/dispatcher.cpp
@@ -38,8 +38,8 @@
   return [] (const Name& prefix,
              const Interest& interest,
              const ControlParameters* params,
-             AcceptContinuation accept,
-             RejectContinuation reject) {
+             const AcceptContinuation& accept,
+             const RejectContinuation& reject) {
     accept("");
   };
 }
@@ -226,8 +226,8 @@
 
 void
 Dispatcher::addStatusDataset(const PartialName& relPrefix,
-                             Authorization authorization,
-                             StatusDatasetHandler handler)
+                             const Authorization& authorization,
+                             const StatusDatasetHandler& handler)
 {
   if (!m_topLevelPrefixes.empty()) {
     BOOST_THROW_EXCEPTION(std::domain_error("one or more top-level prefix has been added"));