fw: rename BroadcastStrategy to MulticastStrategy

BroadcastStrategy is temporarily retained for backwards compatibility.

This commit also updates nfd.conf and ndn-autoconfig to use MulticastStrategy
in place of BroadcastStrategy.

refs #3011

Change-Id: I011f1cf75db26b3c93552f8322a0bba4ce8dd033
diff --git a/tools/ndn-autoconfig/multicast-discovery.cpp b/tools/ndn-autoconfig/multicast-discovery.cpp
index ae3e72d..59a115b 100644
--- a/tools/ndn-autoconfig/multicast-discovery.cpp
+++ b/tools/ndn-autoconfig/multicast-discovery.cpp
@@ -145,7 +145,7 @@
   nfd::ControlParameters parameters;
   parameters
     .setName(LOCALHOP_HUB_DISCOVERY_PREFIX)
-    .setStrategy("/localhost/nfd/strategy/broadcast");
+    .setStrategy("/localhost/nfd/strategy/multicast");
 
   m_controller.start<nfd::StrategyChoiceSetCommand>(parameters,
                                                     bind(&MulticastDiscovery::requestHubData, this),
@@ -156,7 +156,7 @@
 void
 MulticastDiscovery::onSetStrategyFailure(const std::string& error)
 {
-  m_nextStageOnFailure("Failed to set broadcast strategy for " +
+  m_nextStageOnFailure("Failed to set multicast strategy for " +
                        LOCALHOP_HUB_DISCOVERY_PREFIX.toUri() + " namespace (" + error + "). "
                        "Skipping multicast discovery stage");
 }