build: Always build in C++11 mode.

This commit also includes update of websocketpp submodule, as the
previous version has compilation problems on OSX with XCode 6.1

Change-Id: I8c9670d0026d840838d77e610e50679ee5ede7a5
Refs: #1930, #2082
diff --git a/daemon/table/strategy-choice.cpp b/daemon/table/strategy-choice.cpp
index eedbc91..c6d45ad 100644
--- a/daemon/table/strategy-choice.cpp
+++ b/daemon/table/strategy-choice.cpp
@@ -158,7 +158,7 @@
     return shared_ptr<const Name>();
   }
 
-  return make_shared<const Name>(entry->getStrategy().getName());
+  return make_shared<Name>(entry->getStrategy().getName());
 }
 
 static inline bool