Using std/boost make_shared for creating shared pointers

Fixed boost::function nulling issue

examples/testee_server/testee_server.cpp

@@ -124,7 +124,7 @@ int main(int argc, char * argv[]) {
             typedef websocketpp::lib::shared_ptr<websocketpp::lib::thread> thread_ptr;
             std::vector<thread_ptr> ts;
             for (size_t i = 0; i < num_threads; i++) {
-                ts.push_back(thread_ptr(new websocketpp::lib::thread(&server::run, &testee_server)));
+                ts.push_back(websocketpp::lib::make_shared<websocketpp::lib::thread>(&server::run, &testee_server));
             }
 
             for (size_t i = 0; i < num_threads; i++) {